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Bxjiajwns 470 








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Introduchon 9 

Gold and bilvbr: 

The auriferous gravels of the Trinity River basiu, Cal., by J. S. Diller 11 

The economic geology of Caison camp, Hinsdale County, Colo., by E. S. 

Lanen 30 

Geology and mineralization of the upper St. Joe River basin, Idaho, by 

J. T. Pardee 39 

Grold-bearing ground moraine in northwestern Montana, by F. C. Schrader. 62 
Geologic relation of ore deposits in the Elkhom Mountains, Mont., by R. W. 

Stone 75 

Notes on the econcnnic geology of the Ramsey, Talapoosa, and White Horse 

mining districts, in Lyon and Washoe counties, Nov., by J. M. Hill 99 

The ore deposits near Pinos Altos, N. Mex., by Sidney Paige 109 

Survey publications on gold and silver 126 


Metalliferous ore deposits near the Burro Mountains, Grant County, 

N. Mex., by Sidney Paige 131 

Preliminary report on the mineral deposits of Ducktown, Tenn., by W. H. 

Emmons and F. B. Laney 151 

Survey publications on copper 173 

Lkad and zinc: 

Notes on lead and copper deposits in the Bear River Range, Idaho and 

Utah, by R. W. Richards 177 

Lead and zinc deposits in the Metaline mining district, northeastern Wash- 
ington, by Howland Bancroft 188 

Survey publications on lead and zinc 201 

Rare metals: 

The arsenic deposits at Brinton, Va., by F. L. Hess 205 

Survey publications on antimony, chromium, monazite, nickel, platinum, 

quicksilver, tin, tungsten, uranium, vanadium, etc 212 

Iron and manganese: 

Iron ores in the Monte vallo-Columbiana region , Alabama , by Charles B u tts . 215 

Survey publications on iron and manganese ores 231 

Aluminum ores: 

Survey publications on aluminum ores — ^bauxite, cryolite, etc 235 


Survey publications on asphalt 236 

Structural materials: 
Building stone: 

Variegated marble southeast of Calera, Shelby County, Ala., by Charles 

Butts 237 

Supplementary notes on the commercial granites of Massachusetts, by 

T.N.Dale 240 

Survey publications on building stone and road metal 289 


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Structural materials — Continued. page. 

Cement and concrete materials: 

Survey publicationa on cement and concrete materials 291 


Clay near Calhan, El Paso County, Colo., by G. B. Richardson 293 

Clay resources of the Murphysboro quadrangle, Illinois, by E. W. Shaw . 297 

Notes on some clays from Texas, by Alexander Deussen 302 

Survey publications on clays, fuller's earth, etc 352 

Gypsum and plasters: 

Gypsum deposits in Eagle County, Colo., by E. F. Burchard 354 

Survey publications on gypsum and plasters 366 

Lime and magnesite: 

Survey publications on lime and magnesite 367 

Glass sand, etc. : 

Survey publications on glass sand and glasB-making materials 368 


Survey publications on abrasive materials ^ . 369 


P)*eliminary report on a portion of the Idaho phosphate reserve, by R. W. 

Richards and G. R.Mansfield 371 

Rock phosphate near Melrose, Mont., by U. S. Grale 440 

A reconnaissance of the phosphate deposits in western Wyoming, by Eliot 

Blackwelder 452 

Survey publications on phosphates and other mineral fertilizers 482 

Mineral paints: 

Paint shales of Pennsylvania, by B. L. Miller 485 

Survey publications on mineral paints 497 


Survey publications on salines, including salt, borax, and soda 498 

Sulphur and pyripe: 

Sulphur deposits, near Soda Springs, Idaho, by R. W. Richards and J« U. 

Bridges 499 

Survey publications on sulphur and pyrite 504 

Miscellaneous nonmetallic products: 

The types, modes of occurrence, and important deposits of asbestos in the 

United States, by J. S. Diller 505 

Dolomite for flux in the vicinity of Montevallo, Shelby County, Ala., by 

Charles Butte 525 

Graphite near Dillon, Mont., by A. N. Winchell , . 528 

Fluorspar near Deming, N. Mex., by N. H. Darton and E. F. Burchard . . 533 
Survey publications on miscellaneous nonmetallic products — Asbestos, 

barite, feldspar, fluorspar, graphite, mica, quartz, etc 546 

Index 549 

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Plate I. Sketch map of Trinity River bMon, Gal., ihowing unoA of aaritoouB 

gravels of aecoiid and third cycles of erosion 16 

II. Geologic map of the upper St. Joe River basin, fihoshone County, 

Idaho 40 

III. Reconnaissance geologic map of Elkhom Mountains, Mont 76 

IV. Geologic map of the vicinity of tiie. Burro Mountains, Grant County, 

N. Mez 132 

V. Map of Massachusetts showing granitoK}u«nying oenteiB 240 

VI. Map of Central Coastal Plain region of Teoaas, diowing location of 

clay deposits 302 

VII. M«^ of clay and lignite fields near Lena, Fayette County, Tex 308 

VIII. Sketch map of S. O. Tatum farm, near Burton, Fayette County, Tex. 316 

IX. General geologic map of a portion of southwestern Idaho 380 

X. Preliminary geologic map of T. 8 S., R. 42 E 402 

XI. Preliminary geologic map of T. 9 S., R. 42 £ 406 

XII. Preliminary geologic map of T. 8 S., R. 43 E 410 

XIII. Preliminary geologic map of T. 9 S., R. 43 E 414 

XIV. Preliminary geologic map of T. lOS., R. 43E 426 

XV. Preliminary geologic map of T. 13 S., R. 43 E 432 

XVI. Ptelinunary geologic map of T. 14 S., R. 43 E 434 

XVII. Outline map of a portion of western Wyoming and adjacent part of 

Idaho 452 

Figure 1. Section across Trinity River basin from the South Fork Mountains 

to Thompson Peak 13 

2. Section of La Grange mine 16 

3. Section across head of Hupp mine, Sept. 30, 1903 17 

4. Section across part of Hupp mine, August, 1910 18 

5. Section of faulted gravel on Trinity River one-eighth mile above 

the Lowden bridge 19 

6. Section of ancient gravels and tuffs in Redding Creek basin 20 

7. Section of ancient gravels in Shock d Montgomery mine. Hay Fork 

valley 21 

8. Section of bluff east of Union Hill mine 27 

9. Sketch map of a portion of west-central Nevada 100 

10. Map showing geologic relations of fissure veins near Finos Altos, 

N.Mex 110 

11. Specimen from Pacific vein, showing evidence of open fissure filling . 115 

12. Cross section showing comb structure in a small vein 116 

13. Ideal structure section near Cleveland group of claims 122 

14. Sketch showing linear arrangement of sphalerite in the Cleveland 

we 123 

15. Plan and approximate profile of Cleveland tunnel 124 

16. Stereogram showing character of ore layers in Cleveland mine 125 


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Figure 17. Map of the Woodward group of mining claims, north of Tyrone, 

N. Mex 134 

18. Stereogram showing how the juncture of two systems of east- west 

and northeast-southwest fractures dipping toward each other will 
become lower to the east 143 

19. Sketch showing sloping plain at the foot of the Big Burros, now 

dissected, cut during the Quaternary cycle of erosion, and the 
gravels which fill the Mangas Valley 144 

20. Group of pyrite crystals, showing chalcocite along the edges em- 

bedded in sericitized feldspar and quartz 144 

21. Kaolin associated with chalcocitization of pyrite 145 

22. Small veinlet in sericitized feldspar, filled with chalcocite, pyrite, 

and quartz 145 

23. Veinlet showing nodule of pyrite surrounded by chalcocite 146 

24. Sketch showing leaching of eastward-dipping chalcocite veins 

along later vertical veins carrying only limonite 147 

25. Sketch map showing the location of the principal ore deposits in 

the producing portion of the Ducktown district 162 

26. Gross section of the Mary mine, chamber 3 S 163 

27. Plan of 20-fathom level, East Tennessee mine 164 

28. Side elevation of a portion of the Old Tennessee-Cherokee lode 

looking N. 55** W 170 

29. Map showing relation of mining prospects to Bear Biver Range and 

overthrust 178 

30. Topographic map of vicinity of Blackstone mine, west of St. 

Charles, Idaho, showing rock outcrops 181 

31. Plan of Blackstone mine 183 

32. Index map of a part of Washington, showing the location of the 

Metaline mining district 188 

33. Map of southwestern Virginia, showing location of arsenic deposits 

at Brin ton 206 

34. Sketch map showing location of limonite deposit at Shelby, Shelby 

County, Ala 216 

35. Sketch map showing location of limonite deposit 3 miles west of 

Brierfield, Shelby County, Ala 220 

36. Sketch map showing location of iron-ore and marble deposits 

southeast of Calera, Shelby County, Ala 222 

87. Sketch map showing location of hematite ore in Columbiana Moun- 
tain, Shelby County, Ala 225 

38. Banded aplite dike in diorite, Leavitt quarry, Leominster, Mass. . . 243 

39. Structure and dikes at Sullivan quarries, New Bedford, Mass 244 

40. Structure at Beattie & Wilcox quarry. Fall River, Mass 250 

41. Structure at Beattie quarry, Fall River, Mass 251 

42. Structure at Blanchard quarries, Uxbridge, Mass 284 

43. Map of the vicinity of Lena, Fayette County, Tex., showing bore 

holes put down to determine extent of kaolin on Leitenberg 

property 310 

44. Index map of Colorado, showing location of Eagle County 355 

45. Map showing areas of gypsum in Eagle County, Colo 358 

46. Map showing phosphate reserves in Idaho on June 30, 1911 373 

47. Diagram showing distribution of phosphate in a portion of the Idaho 

phosphate reserve 438 

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FiGXTRE 48. Map showing location of phosphate deposits northwest of Melrose, 

Mont 441 

49. View of the phosphate mountain near Melrose, Mont 443 

50. Section across phosphate deposit near Melrose, Mont 446 

51 . Index map showing area in western Wyoming containing phosphate 

deposits 462 

52. Diagrammatic structure section of the Teton Range and vicinity. . 463 

53. Section showing probable structure and relations of beds in the 

Hoback Range just south of Fall River 465 

54. Section showing stracture of the north slope of Gros Ventre Range 

near the mouth of Crystal Greek 467 

55. Diagrammatic section of sedimentary beds in the north slope of the 

Bull Lake basin, on the north side of the Wind River Range . . . 474 

56. Section showing structure of Black Mountain, northwest of the 

Wind River basin 478 

57. Section showing structure of the Owl Greek Mountains in the longi- 

tude of Thermopolis, Wyo 480 

58. Geologic map of sulphur-bearing area near Soda Springs, Idaho 500 

59. Map showing location of asbestos deposits in northern Vermont and 

adjoining portion of Ganada 508 

60. Map of vicinity of Gasper, Wyo., showing Gasper Moimtain and 

Smith Greek asbestos areas 512 

61. Map of Fluorite Ridge and vicinity of Deming, N. Mex., showing 

location of fluorspar deposits 534 

62. Geologic map of Fluorite Ridge, 12 miles north of Deming, N. Mex . 535 

63. Cross section of Fluorite Ridge 536 

64. Section through second opening at Fluorite mines 538 

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C. W. Hates and Waldemab Lindoben, Oeohgists in charge. 


This volume is the ninth of a series that includes Bulletins 213, 225; 
260, 285, 315, 340, 380, and 430, ''Contributions to economic geology" 
for 1902, 1903, 1904, 1905, 1906 (Pt. I), 1907 (Pt. I), 1908 (Pt. I), and 
1909 (Pt. I), respectively. These bulletins are prepared primarily 
to insure prompt publication of the economic results of investigations 
made by the United States Geological Survey. 

As the subtitle indicates, the papers included are of two classes — 
(1) short papers giving comparatively detailed descriptions of occur- 
rences that have economic interest but are not of sufficient importance 
to warrant a more extended description; (2) preliminary reports on 
economic investigations the results of which are to be published later 
in more detailed form. 

These papers are such only as have a direct economic bearing, all 
topics of purely scientific interest being excluded. They have been 
grouped according to the subjects treated, and each group has been 
issued as an advance chapter as soon as it was ready. 

By means of the bibliographies accompanying the several groups of 
papers, these volumes also serve as a guide to the economic publica- 
tions of the Survey and afford a better idea of the work which the 
oiganization is carrying on for the direct advancement of mining 
interests throughout the country than can readily be obtained from 
the more voluminous final reports. 

Brief abstracts of the publications of the year are given in the 
annual report of the Director. The complete list of Survey publica- 


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tions adOFords, by means of finding lists of subjects and of authors, 
further aid in ascertaining the extent of the Survey's work in eco- 
nomic geology. 

Since 1905 the annual economic bulletin has been printed in two 
parts, the second part comprising papers on mineral fuels. These 
volumes for 1906, 1907, 1908, and 1909 are Bulletins 316, 341, 381, 
and 431. Bulletin 471 will form Part II of the "Contributions'' for 

The reports on work in Alaska have been printed in a separate series 
since 1904, the volumes so far issued being Bulletins 259, 284, 314, 
345, 379, 442, and 480. 

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Gold and Silver 


By J. S. DiLLER. 


The Trinity River region, in northwestern California, has long 
been worthily noted for its mines, especially the placers, the working 
of which opened with a rush in the early fifties and has continued 
with more or less regularity ever since. Besides the La Grange mine, 
the largest hydraulic mine now in active operation, it contains the 
Hupp, the Union HiU, and a number of other hydraulic mines, par- 
ticularly in the northern portion of the county. Large bodies of 
gravel of lower grade yet remain. Those near the river level are now 
being attacked by dredges, as at Trinity Center and Poker Bar, and 
the outlook for the future is encouraging. 

The region is accessible by wagon road only from the Southern 
Pacific Railroad in the Sacramento Valley at Redding, the chief point 
of supply, via French Gulch 38 miles to Lewiston, and from Red 
Bluff via Harrison Gulch about 60 miles to Hay Fork. The new 
State road connecting Hay Fork with Humboldt Bay will soon be 
completed, and active surveys promise a railroad witbin a few years 
from the same bay through Hyampom and Hay Fork to the Sacra* 
mento Valley, 

For much of the information used in this paper I am deeply in- 
debted to Mr. Thayer, of Douglas City; Mr. J. J, Murphy, of the Union 
mil mine; Mr. Pierre Bouery, of tiie La Grange mine; Mr. W, D. 
Ayers, of Poker Bar; and Mr. M. D. Pinkerton, of the Globe mine; 
but more particularly to Mr. H. L. Lowden, formerly county surveyor 
of Trinity County, who through many years by maps and conversa- 
tion has given me much information concerning the distribution of 
the auriferous gravels. 


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The Trinity River basin lies wholly within the southern part of the 
Klamath Mountains. The course of Trinity River (see PL I) is 
roughly crescentic, concave to the north. The right arm represents 
the south and southwest upper course of the river to Douglas City, 
where the stream turns and flows northwestward to the Klamath. 

The basin is bordered by prominent mountains. On the north, 
between the arms of the crescent, lie the Salmon Mountains ^ of the 
Sierra Costa cluster, rising to elevations over 8,000 feet. On the 
southeast and south are the Trinity, Bully Choop, and North and 
South Yolla Bolly mountains, ranging from 6,000 to 8,000 feet; on 
the southwest is the prominent, remarkably even crested ridge of 
South Fork Mountain, having an altitude of nearly 6,000 feet. 

The Trinity River basin embraces the whole of Trinity County 
except the south end and also the part of Humboldt County about 
the Hoopa Reservation, the total area being nearly 3,000 square 


The evon crest of the South Fork Mountains is part of an ancient 
plain of erosion, extensively developed in the Klamath Mountains 
and hence called the Klamath peneplain.* This plain is the result of 
the first cycle of erosion recorded in the topography of that region 
and has been differentially uplifted and deformed so that portions of 
the peneplain which appear in the Salmon, Trinity, Yolla Bolly, and 
South Fork mountains are now at different levels. 

Trinity River and its branches, rejuvenated by the uplift, deepened 
and widened its valley during a second cycle of erosion until a second 
plain of erosion was produced within the borders of the Trinity basin. 
This second plain appears to correspond to the Sherwood peneplain 
on the coast. 

The Sherwood peneplain of the Trinity basin is from 500 to 1,000 
feet lower than the bordering mountains showing remnants of the 
Klamath peneplain. It is the general summit level or the plateau of 
the Trinity River basin far above the present streams. The irregu- 
larities of the plateau surface are due in part to the fact that the 
planation of the second cycle was not complete, in part to deforma- 
tion in uplifting the Sherwood peneplain, but perhaps chiefly to 
subsequent erosion of the again rejuvenated Trinity River and its 
tributaries. During a third cycle of erosion the streams deeply 
trenched the Sherwood peneplain and by widening their terraced 
canyons have reduced the plateau to a succession of ridges of approx- 
imately equal elevation. 

1 Ball. U. 8. Qeol. Survey No. 196, 1902, PI. I; footnote, p. 10. The Salmon Mountains have l)een called 
the Siena Costa by O. H. Heishey (Am. Geologist, vol. 25, 1900, p. 70). 
•Bull. U. 8. Geol. Sun-ey No. 190, 1902, p. 15. 

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These two pen^laios, the Klamath and the Sherwood, correspond 
approximatdiy to the remnants of old topographic cycles recognized 
by Hershey ^ in the Trinity region of the Klamath Mountains and to 
those recognized by Lindgr^i ^ in the Sierra Ne- 
vada. Both of these authors regarded the higher 
and older peneplain as of Cretaceous age and the 
lower and newer as Tertiary. 

The relations of these physiographic features 
are illustrated in figure 1, a generalized section 
from the South Fork Moimtains northeastward 
across the Trinity River basin to Thompson Peak. 
The flat summit of the South Fork Mountains and 
the gentle slope on the divide southwest of Thomp- 
son Peak belong to the Klamath peneplain (a). 
The flat-topped ridges (6) in the Trinity River 
basin are remnants of the Sherwood peneplain. 
They are about 1,000 feet below the Klamath 
peneplain. These remnants of the Sherwood 
peneplain are separated by terraced stream val- 
leys (c) more than 2,000 feet deep and ranging 
from Vnahaped canyons or narrow, terraced val- 
leys to broad, flat valleys like that of Hyampom 
and Hay Foric. 


The uplift which closed the second cycle of 
erosion and initiated the third cycle was suffi- 
ciently great to form mountains and was soon 
followed by the development of glaciers which 
extended for comparatively short distances from 
the highest summits down the deepening valleys 
of the rejuvenated streams. As shown by Her* 
shey,* there were many advances and retreats of 
the glacial ice throughout a long period, and the 
glaciers were closely related to the development 
of the valley terraces during the third cycle of 
erosion, when the modem streams were trenching 
their present valleys so deeply below the general 
level of the Sherwood peneplain. 

Glaciers are gravel mills, and the bowlders and 
gravel of the till of the earlier glaciers, having 
thoroughly decomposed, liberated all the gold for concentration by 
stream action in the gravels capping the terraces of the present 

1 Am. Geologist, vol. 25, 1900, pp. 86-87. 

> Age of the auriferous gr&yels of the Sierra Nevada: Jour. Geology, vol. 4, No. 8, 1896, p. 894. 
• The river terraces of the Orleans Basin, California: Bull. Dept. Geology Univ. California, vol. 3, 1904| 
pp. 423-476. 


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streams. As pointed out by MacDonald,* glaciers as agents of ero- 
sion forming the till and thus initiating the concentration of its 
gold in gravels have an economic aspect. 

The only auriferous gravels commingled with glacial deposits, or 
"dead wash," in the Trinity River basin, are on the larger streams 
heading in the higher portions of the Salmon Mountains. The val- 
leys of such streams as Coffee Creek, Swift Creek, and Stewarts Fork 
were occupied by glaciers of considerable size. 


One of the most important conditions contributory to the forma- 
tion of rich auriferous gravels is the deep weathering and disinte- 
gration of rocks that contain gold-bearing quartz veins. By this 
means the gold is liberated in the residual material and prepared 
for concentration by the streams in their gravel beds. That aurif- 
erous gravels commonly originate in connection with peneplains is 
evident in the Sierra Nevada, where the high gravels are associated 
with the low relief of a peneplain and contain a large amount of 
residual material resulting from the deep rock weathering on gentle 



No auriferous gravels have yet been found in immediate connec- 
tion with the Klamath peneplain on the borders of the Trinity River 
basin, but within the basin there are large masses of gravel whose 
origin may possibly be referred back to the EQamath peneplain. If 
this peneplain is regarded as Cretaceous, as claimed by Hershey, 
there is evidence on the eastern border of the Klamath Mountains 
in both Oregon and California that, locally at least, the marine 
gravels of that period are auriferous. H. W. Turner' in 1903 
described *'The Cretaceous auriferous conglomerate of the Cotton- 
wood mining district of Siakiyou County, Cal.," and recently G. F. 
Kay' and others have shown that Cretaceous gravels at several 
locaUties in the northern part of the Klamath Mountains in Oregon 
are auriferous. This Cretaceous auriferous gravel at one time covered 
a lai^e part of the Klamath Mountains, but it has been washed away 
and its gold content concentrated by stream action in richer gravels 
of later age. Of this the Cretaceous f ossilif erous pebbles found in later 
gravels of Trinity River near Lowden's ranch afford good evidence. 

1 MacDonald, D. F., BuU. U. S. Oeol. Survey No. 430, 1910, p. 50. 
s Eng. and Min. Jour., vol. 76, 1903, pp. 653-«64. 
9 Bull. U. 8. G90I. Survey No. 380, 1909, p. 72. 

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Elxtensive deposits of auriferous gravel are associated in laige part 
with the Sherwood peneplain, but their relations to it are such as to 
show that they are older than the final stage of the peneplain and 
most probably originated in connection with an early stage in its 

The preservation of these ancient graveb is due to their having 
been faulted downward into basins where they were protected from 
erosion by a rim of harder rocks. These deposits are outlined on 
the map (PI. I), and the areas will be, considered separately in the 
following paragraphs. The deposits have a wide range in elevation 
and manner of outcrop, but by their tilted stratification and partial 
induration they may be readily distinguished from the much later 
terrace gravels in the deep trenches which Trinity Kiver and its 
tributaries have cut in the Sherwood peneplain. 


The Weaverville Basin attracted attention in the early fifties, and 
ever since has been the scene of more or less vigorous activity in 
placer mining. The area was outlined by me * in 1893 and described 
more fully in 1903 by O. H. Hershey,^ who has kindly furnished a 
geologic map of the region from which I have obtained the outline 
of the north end of the deposits. The area is about 20 miles in length 
from the La Orange mine to a point near Swift Creek and is from 1 to 
3 miles wide. Its surface is a well-marked plain whose ends are of 
nearly equal altitude, approximately 3,100 feet, but whose east side 
is 600 to 800 feet lower than the west side, the plain sloping with the 
transverse drainage directly away from the Salmon Mountains toward 
the present Trinity River. The greatest thickness of the deposit in 
this area is probably not less than 1,000 feet, and the general atti- 
tude of the strata is monoclinal, with a dip of about 26^ W., toward 
the fault which limits the deposit in that direction. 

This fault was first pointed out by D. F. MacDonald * and illus- 
trated, as in figure 2, by a section of the La Orange mine, where it 
lies between the auriferous gravels and Paleozoic black slates on 
the one hand and greenstones on the other. The general strike of 
the fault plane in the mine is N. 64"* E. and the dip 22° SE., but 
its course varies. The fault plane is clearly marked by slickensided 

1 Fourteenth Ann. Kept. U. S. Geol. Survey, pt. 2, 1894, p. 414; aee also Bull. 196, 1902, p. 44, 

' Joor. Geology, vol. U, 1903, p. 157. 

s Ball. U. 8. Geol. Survey No. 430, 1910, p. 51. 

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tracts of crushed dark slate on greenstone, and the strise generally 
run directly down the slope. East of the La Grange mine and reser- 
voir the strike of the fault is N. 87** E., but where the fault crosses 
the West Fork of Weaver Creek its course is nearly north and south. 
Beyond that point it has not been defijoitdy traced. 

The La Grange mine exposes about 600 feet of more or less dis- 
tinctly stratified gravel, which belongs chiefly to the upper portion 
of the Weaverville Basin deposits. According to MacDonald * — 

The wash is fairly fresh and contains a great variety of rock; about 12 per cent of it 
consists of bowlders weighing from 100 pounds to many tons. Near the lower part of 
this bed is a lens-shaped layer of cement gravel having a maximum thickaesi of 50 
feet. Below this indurated bed uncemented stratified wash forms the basal part of 
the younger gravel and rests with apparent imconformity on an older blue gravel. 

The so-called blue gravel rests on an uneven surface of slaty bedrock. It presents 
a much more squeezed and sheared appearance than the uppw giavel and shows many 
stones and bowlders flattened and fmctured. Though not a cement gravel it has a 

FiavR£ 2.— SeoUon of La Qrange mine, near WMverville. By D. F. MacDonald. 

much more resistant matrix than the overlying material and shows more small faults, 
the principal of which trend N. 40** E. and dip 65** SE. The coloring matter, which 
has given the name to the gravel, is probably iron reduced to ferrous compounds by 
an excess of oi^ganic matter. 

The composition and general charact^ of the deposits of the 
Weaverville Basin are best revealed along the branches of Weaver 
Creek in the vicinity of Weaverville, where hydraulic mining has 
been most extensive and is still in progress. The deposits as a whole 
are complex, consisting chiefly of an older succession of fine beds of 
residual material unconformably overlain by later gravds, some of 
which, at least, if not all, are undoubtedly due to the action of modem 

The relations of these gravels are illustrated in figure 3 by a sec- 
tion across the head of the Hupp mine as it appeared September 30, 
1903. The soft rock, which is used in the Hupp mine as the bed- 

1 Op. dt., p. 52. 

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rock for hydrauliddng the overlying gravels, is of special interest in 
that it is made up of residual products from the decomposed rocks 
of the developing Sherwood peneplain. Much of the sand is greenish 
or red from the decomposition products of the ferromagnesian sili- 
cates, or whitish from the kaolin of the decomposed feldspars. The 
quartz grains are sharp and angular, as if moved for a short distance 
only over gentle slopes from their source. Altogether these fine 
sediments tell a story of gentle relief and deep decomposition of the 
surface rocks about the time the Sherwood peneplain was forming, 
the free gold the rocks contained being thus liberated for concentra- 
tion in the stream beds. 

These soft beds, often called ''false bedrock,'' are exposed from 
one side of the basin to the other and with few exceptions dip west- 
ward. On the east side of the basin, where the oldest beds are 
exposed, they consist almost wholly of fine sediments, but on the 
west side, as shown by the lateral gulches of the West Fork of Weaver 
Creek, the tilted soft beds 
contain a larger proportion 
of gravel and the fragments 
are generally angular. 

In the eastern part of the 
basin there are some light- 
colored beds among the Fiouwt3.-Sectlon8croM head ol Hupp mine September 
older ones and they appear *» I^^. o, soft bedrock composed chiefly of fine sand 
. 1^ . /» 1 . •.- with some clay and fine gravel; ft, sand and gravelilUrly 

lO Oe tuns, out positive eVl- ^eU stratUed, with f^ bowlders in some locaUtles but 
dence as to their volcanic ™*°y *>* others (fine gold); c. gravel, Irregular, with 

nature could not be obtained K^^ '^^'' '' ""^ '"'^ "^ '^ 
even imder the microscope. 

These beds contain fragments of leaves that throw some light on 
their age. The beds are evidently very much older than the gravels 
marked b in figure 3, from which they are separated by a marked 
unconformity that represents the tilting of the beds marked a and 
their extensive erosion before the deposition of gravels marked b. 

The b gravels are evidently older than the c, and both may have 
been deposited !>y streams of water, although there are places where 
the material is unassorted and bowlders become prominent, so that 
the deposits somewhat resemble glacial till. 

Figure 4 is a section made in the summer of 1910 of part of the 
Hupp mine near its head. The coarse layer of rotten bowlders that 
unconformably overUes the soft bed is made up of unassorted mate- 
rial, resembling glacial till, although no definite marks of glacial 
action could be found. Many of the bowlders are from 3 to 4 feet in 
diameter and some of them are completely decomposed. In the 
adjacent bluff the same bowlder bed is 25 feet thick and contains 
W174*— Bull. 470-11 2 

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much sand and clay, but its relation to the underlying soft beds of 
the mine is not clearly exposed. 

The bowlder bed, with the overlying material, appears to form a 
large part of the prominent divide between Garden Gulch and the 
East Fork of Weaver Creek and is generally poor in gold. The 
material of which the pebbles and bowlders are for the most part 
composed is hornblende schist or diorite, like that of the mountains 
immediately northwest of the gravel deposit, and it is evident that 
the material was brought into the present gravel area from the north- 
west and not from the northeast, whence came the fine material of 
the soft bedrock. 

In the inclined sand beds that form the false bedrock, as in the 
Hupp mine, small quantities of fine gold are widely distributed, and 
in the gravels of the same beds toward the western edge of the basin, 
as at the La Grange mine, the values are sufficient to afford very 
profitable mining when worked on a large scale. The gravels of the 
later stream beds, where the gold has been concentrated by stream 

Figure 4.— Section across part of Hupp mine In Aagmt, ma •, Soft bad>~tlltodtand, days, and graveli 
of false bedrook; h, bowlder bed In which I to 4 f9ot bowlders are comnion; e, flume. 

action, have been successfully mined for many years, as in the Hupp 
mine. Within the Weaverville Basin the La Grange and Hupp 
mines are the most important placer mines now operating. The day 
of small placer mining is past, but there are yet at a number of places 
in the area large bodies of gravel that should yield a profitable return 
if worked economically on a large scale. 


A considerable area of the old auriferous gravels comparable with 
those of the Weaverville Basin is situated on Dutton Creek south- 
west of Weaverville, but it has not been definitely outlined. The 
gravel extends, but not continuously, for several miles from the head 
of Dutton Creek, at an elevation of about 3,550 feet, in the Sweep- 
stake mine, down to the mouth of Dutton Creek, at an elevation of 
2,200 feet above the sea, or about 400 feet above Trinity River, in the 
Dutton Creek mines. 

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In the Sweepstake mine over 100 feet of gravel is exposed. Some 
of it is fresh, but in the older portion, which is coarse, many of the 
pebbles are completely decomposed to red, yellow, or white residual 

At the Dutton Creek mines the gravel is coarser, with bowlders 6 
to 20 feet in diameter. Some of the pebbles are decomposed and 
many of them incline to the north, as if the stream came from that 
direction. The gravel extends over 600 feet up the slope toward the 
Sweepstake mine and is limited on the west by a north-south rim 
rock that may be due to the faulting which preserved the gravels. 


There are two areas of gravel about the summit of Browns Moun- 
tain. The larger area, just north of the Lowden road, rises to 2,900 
feet about the summit and extends southeastward but does not 
reach the river. The northern area rises above 3,000 feet and some 
of its pebbles are over a foot in diameter. These gravels have not 
been mined and their thickness where greatest does not exceed 500 
feet. They border the mica schist summit of Browns Mountain in 
such a way as to indicate that the mountain was an island in the 
broad stream that deposited the gravels. 


The Lowden area of ancient gravel extends about 5 miles down 
Trinity River from a point near the mouth of Rush Creek. The 
gravel is partly cemented and 
forms the abutment of the 
new bridge above Lowden. 
Near the bridge on the right 
bank of the river there is a 
prominent bluff of stratified 

gravel which dips 26^ W. and ' Fioubs 6.--<8eotion of faulted gravel on Trfnltr River one- 

is separated from the grano- •*«ii*^ f^ "^Z!^ ^""^^ ^"^^^ *' ^*^^ 

^ ° gravel; o, granodlorite. 

diorite by a fault, as shown 

in figure 5. This fault dropped the gravel about 1,200 feet from the 
level of that on Browns Mountain. It strikes N. 25^ E., approxi- 
mately parallel to the general course of the river, and had much to 
do in determining the location of the present bed of the streamr 

Southwest of Lowden the area widens and the gravel in the Last 
Chance mine, well stratified, with finer beds below, strikes approxi- 
mately northeast and dips 26^ NW. The gravels at the Last Chance 
mine are in many places finnly cemented and, like those near the 
Lowden bridge, require blasting in mining. The Last Chance mine 
is not now in operation. Its water goes to operate the Union Hill 

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mine, near Douglas City. The prominent terrace in the great bend 
of Trinity River between the Last Chance and Union Hill mines, as 
well as the flat ridge east of the lower portion of Browns Creek, may 
contain gravels like those of Last Chance, but these localities were not 

The gravels of the Union Hill mine, which is now in operation, are 
uncemented. They lie horizontally on one of the recent terraces of 
Trinity River and are much younger than the ancient gravels of the 
Last Chance mine and Weaverville Basin. So also are the gravels 
now being mined at Poker Flat, only a few feet above the adjacent 
river. These gravels belong to the youngest river terrace, being 
younger even than those of Union Hill. 


*The Redding Creek area lies 7 miles southeast of Douglas City. 
Its length is 5 miles, from Bigelow's, on Browns Creek, northeast 
across Redding Creek and Panwauket Gulch to Indian Creek; its 

Figure d.— Section of ancient gravels and tufb in Redding Creek basin, a. Coal; b, tuff; c, stratified 

auriferous gravel; d, mica schist. 

width is about a mile. The beds strike approximately N. 45^ E. and 
the average dip is 27® SE., toward the limit, which is supposed to be 
due to a fault. Panwauket Gulch and Redding Creek afford the 
section shown in figure 6. 

About 400 feet of partly cemented gravel overlies 250 feet or more, 
of white tuflf, in the upper part of which there is a 50-foot bed of gravel. 
Below the tuffs are shales and thinner beds of tuff and a bed of shaly 
coal ranging from 5 to 15 feet in thickness. This body of auriferous 
gravel, having a total thickness of approximately 900 feet, rests 
directly on the Horsetown formation, of Lower Cretaceous age. 

Panwauket and Redding creeks have cut terraced valleys across 
the tilted gravels and tuffs and the terraces are capped by horizontal 
beds of gravel and sand to a thickness of generally more than 25 feet. 

These later bench gravels are due in large measure to the erosion 
of the older gravels and the concentration of their gold. The later 
gravels have been extensively mined, especially in Panwauket Gulch 
and Indian Creek, and it is estimated on good authority that they 
have yielded nearly a million dollars in gold. 

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The Hay Fork area is one of the largest in the region and extends 
throughout the Hay Fork valley, but the beds are generally concealed 
by a great expanse of alluvium of the local peneplain developed on 
the soft beds. like the Weaverville, Lowden, and Redding Creek 
basinS; the Hay Fork basin is due to faulting. The great dislocation 
is along the south, side, where in consequence the latest beds of the 
mass are to be found. Outcrops are numerous along the north side 
of the basin, where large bodies of more or less firmly cemented 
gravels occur and have been nuned. At the Shock & Montgomery 
mine the section given in figure 7 was measured. There are 88 feet 
of whitish tuffs overlying 550 feet of gravels interbedded with small 
layers of sand, which rest with apparent conformity on Cretaceous 
shales. The pebbles of these gravels are rarely as much as 4 inches 
in diameter. The whole succession of strata strike N. 63° E. and 
dip 35° SE. 

Gravels overlain by tuffs and associated with shales and shaly 
coal occur from 1 to 2 miles northwest of Hay Fork post office but are 
much finer and not so thick as those toward the east end of the basin. 
The gravels disappear entirely before reaching the southwest end of 
the valley, where the 
coal associated with 
shale rests directly on 
altered greenstone. 

Shales and tuffs with 
a few thin layers of 

travel and rarelv flhalv Fsovbx?.— Sectkm of uolentgravfllB in Shocks Montgomery mine, 
^iair«7i aixvx x»icijr aua^J H»y Fork vaUey. a, StraUfled gravels; ^ Cretaceous shale. 

coal occur along Hay 

Fork in the middle portion of the valley as well as along its southern 
border, and locally they are full of fossil shells and leaves. The dip 
throughout is southerly, toward the fault which limits the beds in 
that direction. The newer beds lie along the southeast side of the 
basin and contain not over 15 per cent of gravel, all of which is fine. 
In this respect the Hay Fork and Redding Creek sections are in strong 

The total thickness of the tilted gravels and shales in the Hay 
Fork area must be much over 1,000 feet. They are unconformably 
overlain throughout the greater portion of the valley by alluvial 
gravels from 5 to 12 feet in thickness. These later gravels have been 
mined locally in a small way. 


Hyampom Valley, at the junction of Hay Fork and South Fork of 
Trinity River, contains a large body of tilted gravels, sands, and 

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clays with a few beds of coal and tuflF. The whole succession lies 
unconformably between the horizontal terrace gravels of the present 
streams and the much older igneous rocks. 

Hyampom Valley has a length of 3 or 4 miles and a width of a mile 
or more. The area as outlined on the map (PI. I) is a close approxi- 
mation determined in the field. It is believed that the soft bcfds under 
consideration are limited to the valley proper. 

Gravels appear on the northeast side of the valley nearly 1,000 
feet above the valley floor and also on Pelletreau Creek along the 
west side of the valley, where 60 feet of gravel and sand is firmly 
cemented and dips 30** E. The most prominent exposures, how- 
ever, are along Hay Fork at the mouth of its canyon, where the 
following section appears: 

Section at mouth of Hay Fork canyon. 


Conglomerate 100 

Shaly coal 5 

Sandstone, micaceoufl, residual; contains concretions 70 

Conglomerate 25 

Greenstone; bluff rises abruptly. 

In the middle portion of the valley there are some fine laminated 
shale, beds of tuff, and several exposures of shaly coal 5 to 10 feet 
thick, making the total thickness of soft beds in the Hyampom area 
nearly 1,000 feet. 

These beds, as shown by their fossil contents, composition, attitude, 
and relation to other formations, belong to the same geologic horizon 
as the tilted beds of the Hay Fork area, although I am not sure that 
they are auriferous. 


On Trinity Biver at Big Bar, sometimes called Coxs Bar, there is a 
small mass of soft shales, sandstones, and some gravels with inclined 
stratification like the beds in the Weaverville Basin. These, though 
sometimes mined, are generally used as bedrock for mining the bench 
gravels of Trinity River that cap the terrace. 

These fine beds are especiaUy rich in fossil leaves, among which 
F. H. Knowlton identifies four species that clearly show the beds to 
belong to the second cycle. They are associated with a small mass 
of Jurassic strata and have probably been faulted down into the older 
rocks and thus preserved. 

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Light-colored tuffs are associated with the gravels of the second 
cycle in the Reading Creek, Hay Fork, and Hyampom areas and 
probably also in the Weaverville Basin. To judge from the decrease 
in the volume of the tuff toward the west, as well as in the size of the 
particles of which it is composed, its source appears to have been in 
tho vicinity of Lassen Peak, where lavas of similar composition occur. 
For the purpose of comparison an analysis of the tuff from Hay Fork 
has recently been made by R. C. Wells in the United States Geological 
Survey laboratoty. Other analyses of the tuff are given in the table 
below, and analyses of the acidic lavas of the Lassen Peak region may 
be found in Survey Bulletin 228, pages 211-213. 

These tuffs associated with the gravels of the second cycle in the 
Trinity River basin are probably of essentially the same horizon as 
the rhyolite tuffs that overUe the bench gravels of the Sierra Nevada. 
This view, as we shall see presently, is fully sustained by the fossil* 
leaves which they contain. 

Chemical analyses of tuffs associated toith aurtferous gravels. 

near post 

Hay Fork. 

of Salt 



east of 

West Fork 









18. M 



























7a 01 









The finer beds, especiaUy the volcanic tuffs, associated with the 
gravels of the second cycle at Weaverville, Reading Creek, Hay Fork, 
Hyampom, and Coxs Bar contain fossil leaves which have been 
studied by F. H. Enowlton at different times from 1902 to 1910. His 
determinations are given in the following table: 

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Fo89il plants from the aurtferou* ffraveU of the seamd cycle in Trinity River 


Lauras ferandisLx. 

Lauras (?) 


Sequoia umoeolata Lx 

Sequoia aogastifoiia Lx 

Sequoia lancsdorflHBrgt.) Heer. 

Populus linoxreni Knowltoxi 


Populus saddachl (77) 

Persea pseudocaromiaisls Lx 

Aov benderi Lx. 




Quercusoonyexa Lx. 




Flcns ungeiri (?) Lx. . . . 

Aralia whitueyi Lx. . 



Jn glan-f |pr*h Imp arl Lx. 


Rhamnus (?) sp 



Taxites olriki (?)(Heer-Lx.) 


Taxodiuxu rft gUchm ift Tnt <>n^^ im Lx . 


ICagnolla lanoeolata Lx 

Magnolia sp., perhaps new 

Taxodium tinajoram Heer 





















Con Bar. 


All the fossil leaves thus far known in the auriferous gravels of the 
second cycle in the Trinity River basin are given in the table. 
Concerning the fossils collected in 1910 Knowlton makes the follow- 
ing report: 

The plants enumerated above all belong to well-known auriferoufl-gravels species, 
and I have no hesitation in pronourcing them to be of the approximate position of 
the auriferous, namely, Miocene. 

On looking back over reports made in previous years on material from the same 
or near-by localities it appears that the conclusion to be drawn is the same in all 
(»8es — that is, the age is approximately the same as that of the auriferous-gravels 

The fossil flora as interpreted by Eaiowlton leaves no doubt as to 
the essential synchroneity of the auriferous gravels of the ELlamath 
Mountains and of the Sierra Nevada. To be more precise, taking 
into account the tuffs, the gravels of the second cycle in the Trinity 
River basin correspond to the bench gravels and gravels of the rhyo- 
litic epoch in the Sierra Nevada, both of which are of Miocene age.^ 

1 The only shell found in the leaf-bearing strata oocun abundantly at Hay Fork. W. H. DaU reports 
it to be a large Viotparaj compares it with aspedes frnmd in the Cretaoeons, and remarks that the genos is 
extinct in (^alllomia recent fauna. 

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The distribution of the gravels of the second cycle aligns closely 
with the Trinity River basin. It has the same prominent curve 
around the south end of the Salmon Mountains and represents the 
Miocene stage of Trinity Kiver, which then flowed in the broad valley 
that finally became the Sherwood peneplain. It appears that at one 
time the master stream of the basin flowed with very low grade by 
way of Hay Fork and Hyampom. The faulting that displaced and 
preserved the gravels finally led to the shifting of the main stream 
to its present course. 


The fact that the La Grange mine is in the gravels of the second 
cycle is an indication of their economic value where they are in large 
bodies practically xmcemented ahd advantageously located. The La 
Grange mine is already well known. It has been described by D. F. 
Campbell^ and D. F. MacDonald,' to whose publications reference 
should be made for details. 

The Hupp mine; at Weaverville, is in gravel that is for the most 
part much younger than that of the La Grange mine and represents 
a higher degree of concentration^ but the conditions are not so favor- 
able for handling large bodies of gravel as at the La Grange. The 
bedrock of the minC; as shown in figures 5 and 6^ is in the soft sand- 
stones, shaleS; and gravels of the tilted strata that fill the Weaver- 
viUe Basin, and the bedrock level at an altitude of 2,200 feet above 
the sea is only about 25 feet above that of the East Fork of Weaver 

As far as I am aware, none of the gravel mines northeast of Weaver- 
ville are wholly in the gravels of the second cycle. 

An attempt has been made to work the gravels of the second cycle 
near Lowden and also in the Last Chance mine, 3 miles southwest 
of Lowden, near the road to Douglas City. A good supply of water 
by a ditch about 8 miles in length was obtained from Grass Valley 
Chreek. The gravel, though but weakly cemented, is so firm as to 
withstand the dash of the water as applied, and on this account the 
mine has made but little progress. The property is now controlled 
and the water used by the Union Hill Hydraulic Co. 

In the Hay Fork area the gravels are feebly cemented but have 
been mined to a small extent by Shock & Montgomery at one place 
near the east end of the valley. The mining thus far has been con- 
fined to the disintegrated material of the surface. Deep cuts have 

I Min. and Sd. Press, toI. 97, Oct. 10, 1906, p. 491. 
B BuU. U. S. Oeol. Survey No. 430, 1910, pp. 51-^66. 

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been washed in the same gravels 2 miles farther northeast, at Macks, 
exposing a fine body of partly cemented gravel, but work was not long 


The gravels of the third cycle are confined to the canyons and 
narrow valleys of the present streams and include not only the gravels 
capping the terraces on the valley slopes but also those in the present 
stream beds. Their distribution is roughly outlined in Plate I (p. 
16) for the purpose of contrasting it with the distribution of the 
gravels of the second cycle. 

In general, the gravels of the third cycle should contain the most 
highly concentrated values. Furthermore, they can be most easily 
and economically mined, because they are entirely imcemented and 
most readily reached by water for piping. 

These are the gravels so extensively mined in the early days. The 
most available and probably the richest have been washed away, 
but still there is much left that may pay well for economical mining 
on a large scale. 

The benches mined by hydraulic methods generally lay between 
25 and 400 feet above the level of Trinity River. Many of these 
mines are still active during the spring. In 1908 there were in Trinity 
Coimty 66 producing placers, of which 49 were hydraulic, 3 drift, 
and 14 surface. But few of them are in operation during the summer. 
About Weaverville and Douglas City the only placers in operation 
in July, 1910, besides the La Grange and Hupp mines, already noted, 
were the Union Hill and Poker Bar, concerning which brief notes 
are added here. 

The Union Hill mine is working gravels of the third cycle on a 
large terrace 175 feet above Trinity River. The mine was started 
in 1862 by Marshall & Mason, who used water from Weaver Creek. 
It remained inactive for a number of years imtil purchased in 1906 
by the present owner, the Union Hill Hydraulic Co., which obtained 
control of the water for the Last Chance mine and brought it to 
Union Hill. The source of the water is Grass Valley Creek. The 
ditches, fimnes, pipes, and tunnels are said to be about 15 miles in 
length and carry sufficient water to run two 7-inch giants 23 out of 
24 hours for nearly half the year under a head from the reservoir of 
450 feet. 

A section of the bluff on the east side of the mine is given in figure 8. 
In the upper 116 feet the deposits are decidedly red and not clearly 
stratified. Below this is 19 feet of blue gravels, sands, and clays, all 
of which are well stratified. Nearly all the values are foimd in the 
blue gravel at the bottom on the mica schist bedrock. 

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On the west side of the mine toward Weaver Creek there are several 
channels due to shifting currents during the deposition of the gravels. 
A rather striking feature of the gravels is the imbrication or overlap- 
ping of the pebbles to the northwest, indicating that the current bj 
which they were placed in position was flowing in that direction from 
Trinity Kiver toward Weaver Creek. 

A matter of special interest is the occurrence of bones and shells 
in the strata associated with the coaly layer near the base of the 
bluff on the east side of the Union Hill mine. Among the shells ^ 
at the base of the coaly layer W. H. Dall has identified Planorhis 
tumens Carpenter, P. vermicularis Gould, and P. cerUervUleTisis 
Tryon, besides some young shells of two other genera. All these 
shells are living fresh-water species in California to-day. 

The small lot of bones found in the layer overlying the coaly bed 
were examined by J. W. Gidley, who reports '' representatives of the 
genera OdocoUeus, Elephaa, and Megaicmyx.'^ He says ''the speci- 
mens are too fragmentary to 
determine the species with 

These fossil shells and 
bones and the physiographic 
relations of the strata con- 
taining them show that the 
gravels of Union Hill are cer- 
tainly Pleistocene in age and 
very much younger than the 
gravels of the earlier cycles. 

The Poker Bar Dredging 
Co. began operations with a 
new plant in the summer of 
1910 on a large bar only a 
few feet above the level of 
the adjacent Trinity River. 

The principal part of the 
plant is a stationary bucket 
dredge to raise the gravel 20 
feet. The dredge pit is 20 feet deep, reaching through the gravel 5 
feet into the bedrock. There are two centrifugal pumps to supply 
the nozzles with water — one from the river to wash the gravel into 
the pit to the elevator and the other from the pit to wash the gravel 
from the elevator down the flume. 

1 A immbflr of good ahells from thia mine were proented to me by Mr. Pierre Booery, of the La Oransa 
mine. The other sheUe In their original matrix as well as all the bones obtained were presented by Mr. 
J. J. ICnrphy, superintendent at Union Hill. 

FiouBE 8.— Section of bluff east of Union Hill mine. 
a, Chiefly red clay, some sandy day, and locally fine 
gravel, 116 feet; b, shaly sandy bed, some bluish gray, 
8 feet; e, shaly fragments of schist, bluish gray, 2 feet; 
d, ooely lay6r,2 to 3 feet; e, ooarse grarel, bluish gray, 3 to 
10 feet; /, mloa schist bedrock. 

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The plant was not quite completed when I saw it in July, 1910. 
Seven men will be required in a shift, and it is expected that 500 
cubic yards of gravel will be handled by three shifts in 24 hours. 
The sluice is 100 feet long, 2 feet wide, and 2 feet deep, with two 
rows of wooden blocks. A small dynamo supplies the electricity for 
lighting the plant. 



It is probable that with a strong water supply under pressure 
having a head, as at the La Grange mine, of 450 to 650 feet, much of 
the gravel of the second cycle that is favorably located could be 
successfully mined. Some of it would probably require blasting. At 
the La Grange, however, by imdercutting, the cemented portion is 
crushed by the superincumbent load. At this mine the gravels are 
most favorably exposed, but farther northeast, along the faulted 
border of the Weaverville Basin, these gravels have been in large part 
washed away by the mountain streams or covered up by the over- 
lapping "dead wash" from the Salmon Mountains. It is probable, 
however, that there are considerable areas, including the Browns 
Mountain areas, which with the fine water supply available could be 
worked to advantage. 

Browns Creek, Reading Creek, Indian Creek, and Grass Valley 
Creek each carries a considerable though not large water supply that 
might be turned in upon the gravels of the Reading Creek basin, 
where the conditions are favorable for mining. 

In general, the gravels of the second cycle where too firmly cemented 
for hydraulicking are not sufficiently rich to warrant crushing. They 
should, however, be carefully prospected, for it is possible that some 
parts rich enough may be found. This perhaps is less probable if we 
consider the mode of origin. These gravels are of fluviatile origin, 
but gravels sufficiently rich to crush, as shown by G. F. Becker,* are 
generally of marine origin. 

The gravels of the third cycle are more widely distributed but of 
less volume than those of the second cycle, and as they present less 
formidable obstacles to mining they are receiving more attention. 
Most of the country is timbered and dumping facilities are generally 
ample and not so restricted by antidfibris laws as in the Sierra Nevada. 
With a fair water supply from the higher mountains conditions are 
favorable for mining. 

1 Eighteenth Ann. Rapt. U. S. Qeol. Survey, pt. 5, 1897, p. 183. 

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In general, the gravels have been richest on streams heading in the 
Salmon, Trinity, and Bully Choop mountains and decrease somewhat 
in value as the distance from the source increases. 

The large values of the Coffee Creek region are well known and it 
is believed that the extensive bodies of gravel on the bars and benches 
of the upper part of Trinity River are well worthy of investigation. 
If the dredges already started at Trinity Center and Poker Bar prove 
as successful as they promise to be a new impetus will be given to 
placer mining. 

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By EsPER S. Larsen. 


The mining camp of Carson is located in Hinsdale Comity, Colo., 
within the area called the San Cristobal quadrangle, about 13 miles 
in an air line west of 3outh of Lake City, which is the nearest railroad 
point. The Continental Divide is 12,360 feet above sea level at 
Carson Pass and the prospects of the camp are located on both sides 
of it. The topography is that characteristic of the high portions of 
the San Juan Mountains, with rugged peaks reaching nearly 14,000 
feet, while the bed of Lake Fork of the Gunnison, only a few miles 
away, is over 5,000 feet below. 

Carson is reached by a wagon road from Lake City, a distance of 
about 20 miles. The road up Lake Fork of the Gunnison is good, 
but from the mouth of Wager Gulch, where the Carson road branches 
from the main road, the climb to the Continental Divide is very steep 
and the wagon road has been washed out so as to be hardly passable 
to wagons. The road continues beyond the divide into Lost Trail 
Creek, but much of this part is very boggy. A good trail folloves 
down Lost Trail Creek to the Rio Grande, where it joins the road 
between Creede and Silverton. 


The camp was discovered about 1881 and reached its greatest 
development in 1889, when there were more than 250 people there. 
The prosperity of the camp was short lived, and in 1893 the mines 
were closed, owing, it is said, to the low price of silver. Since that 
time the camp has had only 10 or 20 prospectors and when visited in 
the smnmer of 1909 there were only six prospectors there. About 
10 years ago the owners of the Batchelor mine carried on extensive 
prospecting, and for a time there was considerable activity at Batche- 
lor, a part of the camp on the north side of the divide. 

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The ore deposits of Carson were examined during the summer of 

1909 in connection with the geologic survey of the San Cristobal 

quadrangle, in charge of Whitman Cross. The general report on 

the geology of the quadrangle will be published as the San Cristobal 



The principal rocks of the region are Tertiary volcanic rocks, but 
Lake Fork of Gunnison Kiver has eroded tlirough these volcanics 
and has cut for a considerable distance into the underljdng pre- 
Cambrian rocks. The pre-Cambrian is made up chiefly of granite 
and quartz monzonite, but dikes of quartz-bearing diabase occur at 
Sherman and are there associated with the mineralization. The 
pre-Cambrian rocks extend up Wager Gulch to an elevation of 10,300 
feet and are overlain by andesitic rocks which probably belong to 
the Silverton volcanic series, either to the pyroxene andesite or to 
the earlier Pica3rune andesite of that series.^ A short distance to the 
west a considerable thickness of the Picayune andesite of the Silver- 
ton volcanic series underlies these andesites. Unconformably over- 
lying the Silverton series is the Fotosi volcanic series, consisting of 
flows, tuff-breccias, and intrusive rocks. The rocks most closely 
associated with the mineralization at Carson are the pre-Potosi 
andesites and the Potosi volcanic series. 


The series of andesites and quartz latites beneath the Potosi vol- 
canic series is made up chiefly of lava flows, but thin breccia beds 
occur between the flows; intrusive rocks may also be present. The 
flows lie nearly flat, and in Wager Gulch they extend from the pre- 
Cambrian rocks to Carson Pass and attain a thickness of nearly 2,000 
feet. A few miles to the east these flows overlie tuffs and flows that 
belong to the Picayune andesite of the Silverton volcanic series, and 
they may be an upper massive part of the Picayune andesite or they 
may belong to the overlying pyroxene andesite. This point has not 
yet been definitely determined. The rocks are green, gray, or 
purplish and show numerous plates of plagioclase, some biotite and 
hornblende, and locally pyroxene, in an aphanitic groundmass. 
Microscopically they are mostly holocrystalline, porphyritic, with 
numerous zoned crystals of plagioclase having an average composi- 
tion of Ab^AB^ and about equal quantities of biotite and resorbed 
hornblende in a groundmass of quartz and orthodase in micro- 
graphic intergrowth. In places augite and hypersth^ie displace 

1 For a more detafied description of the Tertiary lavas of this region the reader Is referred to the SHverton 
folto(N<w lao). OmI. Atlaa U. B„ U. S. QeoL Survey, igos. 

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the biotite and hornblende in whole or in part, and this is especially 
common in the lower flows. Some of the flows have little quartz 
and orthoclase in the groundmass. The rocks range from quartz 
latites to pyroxene andesites. 


The Potosi volcanic series is itself made up of a complex of nearly 
horizontal lava flows, fragmental material, and intrusive rocks. with 
compositions varying from that of a rhyolite to that of a basic andes- 
ite. The relations of the various rocks have not yet been fully un- 
raveled and the conclusions of this paper are subject to modification. 

Rhydites and quartz latites, — ^The lowest member consists of several 
flows of quartz latites and rhyolites. The rocks are almost invariably 
light red in color and usually have a zone of black glass at the base 
and the top. The rhyolites are platy from flow and have numerous 
large, flattened gas cavities. They break down into soft slopes cov- 
ered with small fragments of rock. Megascopically they show a few 
crystals of biotite and feldspar in a felsitic groundmass. Microscopi- 
cally they are usually in part spheruUtic in texture. The quartz 
latites are much nearer the rhyolites than are those of the underlying 
pre-Potosi rocks or of the basic members of the Potosi. They are 
also cavernous and break into thick plates. However, they are much 
more resistant than the rhyolites and usually outcrop as cliffs. The 
hand specimen shows numerous crystals of white plagioclase and 
biotite and some specimens contain glassy orthoclase, quartz, horn- 
blende, and augite. The thin sections show numerous phenocry^ts 
of plagioclase, about andesino-labradorite in composition, some 
biotite, and usually orthoclase, quartz, hornblende, and augite; 
zircon, apatite, iron ore, and sphene are accessory. As a rule the 
groundmass tends to be spherulitic. This series varies greatly in 
thickness and in places may be absent altogether. 

Agglomeraie. — ^The formation of this rhyolite series was followed by 
a period of erosion, after which there was erupted from a local center 
a large amount of fragmental andesite. This andesitic agglomerate 
occurs in a lenslike mass which attains a thickness of 1 ,500 feet or more 
in Lost Trail Gulch but becomes rapidly thinner to the southeast and 
pinches out entirely only a few mUes down the Rio Grande. The 
material is rudely sorted and poorly bedded and consists of subangular 
blocks and waterwom bowlders, up to several feet in diameter, in a 
tuffaceous matrix. The pebbles are made up, for the greater part, 
of pyroxene andesite, but hornblende-pyroxene andesite is common 
and biotite andesite, quartz latite, and rhyolite are sometimes seen. 
Most of the rocks have much glass in the groundmass. Within the 
breccia and closely associated with it in origin are many dikes and 
sills of andesite and quartz latite. They are especially abundant near 

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Carson. A few lava flows occur within the agglomerate, and they are 
moro numerous near the top of the series. The agglomerate appears 
to be a mass predominantly of andesitic material, deposited subaerially , 
with subordinate stream action, about a volcanic vent with its center 
near Carson. 

QiMrtz diorUe. — On the southeast shoulder of Bent Peak, just 
southwest of the Lost Trail mine, there is a considerable body of 
quartz diorite intrusive in the a^lomerate. It is rather fine grained 
and is greenish gray in color. The thin section of the typical rock 
shows very numerous crystals of andesine-labradorite feldspar, consid- 
erable uralitized augite, and some biotite in a subordinate amount of 
interstitial quartz and orthoclase. Border phases of the rock contain 
more quartz and orthoclase and are distinctly porphyritic. A similar 
intrusive occurs a few miles to the southwest in West Lost Trail Qulch. 
A specimen of a similar rock was collected at the Batchelor mine. 

RhyolUeB ani quartz IcUites. — During the period in which the 
andesitic breccia was accumulating about the Carson vent the normal 
rhyolites and quartz latites of the Potosi series were being extruded 
from other vents and these flows interfingered with the andesitic 
material to a greater or less extent. After the activity of the Carson 
vent ceased these rhyolites and latites covered up the andesitic series. 

Quartz latites chamcterized by large phenocrysts, — ^The last stage of 

Potosi eruption represented near Carson is the series of flows and 

associated breccias made up of less siliceous quartz latites. They 

are characterized by the large size of the phenocrysts of feldspar, 

some of which are an inch or more across. The rocks are usually red 

or gray and in the hand specimen show, besides the feldspar, biotite, 

hornblende, green augite, and locally quartz. Under the microscope 

the rock shows numerous phenocrysts of labradorite, some augite and 

resorbed biotite, and in some sections hypersthene and hornblende in 

a holocrystalline mass made up of laths of andesine feldspar, quartz, 

and orthoclase. 


The mineraUzation is confined to the vicinity of the Carson volcanic 
center and has affected chiefly the quartz latites and andesites beneath 
the Potosi series and the quartz diorite, but the agglomerate near the 
vent and other rocks may also be mineraUzed. Zones of decomposed 
and mineraUzed porphyry are very numerous. As a rule they do not 
seem to follow clear-cut fault planes but are associated with irregular 
fractures and gashes and are not generally continuous for more than 
a few hundred feet. Three types of alteration were noticed. In the 
most common type the rock is white, the feldspars are sericitized, the 
dark minerals are leached out, and pyrite is disseminated throughout 
the rock; the original porphyritic character of the rock is ytill easily 

94174'— Bull. 470—11 3 

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seen. In another type of alteration, nrliicfa is usually found near tike 
vein filling, the ordinal texture is still perceptible, tiie rock has been 
enriched in quartz, and the original f eldspathk material is represented 
by alunite and a little kaolinite; pyrite is abundant. The third type 
is due to more intense mineralization and consists of the complete 
replacement of the groundmass by quartz, while the feldspar pfaeno- 
crysts are nearly or completely leached out aod are represented by 
cavities lined with drusy quartz, ^lai^gtte, sphalerite, or other sulphides. 

The ore itself is invariably associated with the zones of decomposition 
in the porphyry. However, the decomposed porphyry was rarely 
observed to carry disseminated ore minerals, but these mixm*ab are 
found chiefly filling open cracks and cavities in ihe decomposed 
porphyry. As a rule the cavities are only partly filled with vein 
matmal, leaving numerous druses and open spaces. The under- 
ground workings were not generally open to inapection, but fn»n the 
observations which were possible and from tiie statements of the 
prospectors it appears that the ore material is usually not over a few 
inches in thickness, though it may reach 18 inches. It is said that 
in places the (M*e' bodies are persistent for hundreds of feet, but as far 
as could be observed the ore is as a ride only locally developed within 
the vein and much of the mineralization took place at cross fractures. 
So far as can be determined from the meager data available, the Tetns 
do not all strike in the same direction, but there is probably some 
tendency for them to strike west of north, as does the St. Jacob vein. 

The minerals of the vein filling are barite, quartz, enargite, pyrite, 
chalcopyrite, sphalerite, galena, marcasite, famatinite, etc. Barite, 
which 19 the chief gangue mineral, occurs as large flat tablets projecting 
into the cavities or as more massive vein filling. Quartz occurs rarely 
in drusy coatings on the wall rock. Enargite, the chief metallic min- 
eral, occurs as well-developed crystals eitho* embedded in barite or 
projecting into druses or as massive material oem^iting breootated 
silicified country rock. Pyrite is sparsely disseminated throu^ the 
enargite. It is more abundant in the decomposed country rock and 
is in places more or less concentrated as the vein filling is approached. 
In one of the tunnels in Wager Gulch a considerable body of massive 
pyrite is exposed. Fibrous, botryoidal marcasite was found coat- 
ing crystals of barite and enargite. Chalcopyrite occurs sparingly 
in the enargite. Sphalerite and galenite usually occur together as 
botryoidal coatings on barite and enargite or as vein filling associated 
with gouge or filling cavities in the decomposed porphyry. 

Four stages of the mineralization can be distinguished. During 
the earliest stage the country rock was altered to a quartznaericite- 
pyrite rock, or to a quartz-alunite-pyrite rock, or finally to a quartz- 
pyrite rock. During the second stage the open spaces were partly 
filled with barite and enargite, with some pyrite, chalcopyrite, etc. 

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The third stage was eharacterized by the deposition of galenite and 
sphalerite. Finally, coatings oi marcaaite were deposited on the 
other minerals. 

The recent glaciation and the rapid erosion in these nigged moun- 
tains has prevented the formation of a deep zone of oxidized ore. 
Moreover, while the underground water level is very irregular, it is 
everywhere near the surface. Indeed, tibe primary sulphide ore 
extends nearly or quite to the surface. However, some of the very 
rich ore mined in the eariy days of the camp and described as ''soft 
talc ore" was probably secondary. 


Accurate data r^arding the values of the ore were not available, 
but from the best information that could be obtained the following 
statements are made. The values lie chiefly in the barite-enargite ore, 
but much of the galena and sphalerite ore is rich in silver. Tlie ore 
is said to have run from $50 to $500 a ton, or even higher, in carload 
lots. The chief value lies in the silver, as there are about 100 ounces 
of silver to 1 ounce of gold. The copper content reaches 15 per cent. 
The ores seem to be of high grade, but their occurrence in very narrow 
irregular veins renders mining expensive. 


Above the forks of Wager Gulch, about a mile below Batchelor, 
there is some limonite at the upper edge of a large bog. It may have 
been deposited by springs coming out from the base of the cUfTs and 
flowing into the bog. The material was mined at one time and hauled 
to Lake City as a flux for the smelter at that place. 


A large amount of prospecting has been carried on at this camp 
and on sev^al of the properties considerable development work has 
been done. Small bodies of ore are found at very many places, but 
only two of the mines have shipped ore. The data available for 
descriptions of the mines and the figures showing the production are 
rather meager but will afford some idea of the conditions. 

8t. Jacob grouf. — The St. Jacob group of mines is the only property 
which has produced any considerable quantity of ore. It was worked 
extensively for several years after 1889 and is said to have produced 
ore valued at $150,000. The ore was valuable chiefly for its content 
of silver, though it contained some gold and copper. The property 
is equipped with a steam hoisting plant and considerable work has 
been done. The main shaft reaches a depth of 300 feet and drifts have 
been run at this level for about 600 feat dong the vein, which strikes 

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west of north. At a depth of 240 feet is another level of about the 
same length. The workings were not accessible, but it is said that 
the vein is about 2 to 3 feet across, with 4 to 14 inches of solid ore, 
and has been followed for about 600 feet. There are several less 
important shafts and levels on the property. The ore consists of 
enargite, barite, quartz, pyrite, chalcopyrite, galena, sphalerite, and 
marcasite. The galena and sphalerite occur as coatings on the barite 
and enargite; the marcasite as botryoidal, spherulitic crusts on the 
barite and enargite. Druses and open spaces are very common. The 
ore is frozen tightly to the wall rock, which is silicified porphyry. 

Lost Trail mine, — ^The Lost Trail mine belongs to the Continental 
Mining Co. and is located south of the divide, just southwest of the 
St. Jacob. A lower tunnel has been run 1,200 feet into the hillside 
and an upper tunnel nearly as far. Some ore has been found, but so 
far as could be obsefr-ed it occurs in stringers only a few inches wide 
and extends along the strike for only a short distance. The vein 
material did not completely fill the fracture, as drusy cavities are 
common. The ore is largely enargite with some pyrite and chalco- 
pyrite in a gangue of barite. In some places the silicified country 
rock contains impregnations of the sulphides. 

Continental group. — ^The Continental group, which also belongs to 
the Continental Mining Co., is located just north of the divide. One 
property of this group, the George III, is said to have produced about 
$50,000 worth of ore similar to that of the St. Jacob. It is said to 
have run from $40 to $140 a ton in carload lots. Several small ore 
bodies have been prospected in this property. A new tunnel a few 
hundred feet southeast of the George III has cut a stringer, about 
an inch across, of a soft ore rich in galena, with chalcopyrite, etc., in 
a soft gougelike gangue. To the west there is a prospect which has 
cut a crushed zone in the porphyry and this silicified porphyry is 
cemented by coarsely crystalline enargite with some pyrite, chalco, 
pyrite, and barite, giving an association of minerals which closely 
resembles that of the Lost Trail mine. As usual, the mineral does 
not fill the cavities. 

About midway between the George III and the Batchelor mine 
there is a short tunnel which cuts across a large body of massive 
pyrite. The tunnel runs in solid pyrite for about 15 feet, but the form 
of the body could not be determined. Drusy cavities in the pyrite 
contain a very few crystals of sphalerite. Tliis body is worthy of 
more careful prospecting. 

Batchelor mine. — ^The Batchelor naine is located in Wager Gulch 
about a mile north of the divide. It is provided with two hoists and 
a rather elaborate surface equipment. The deepest shaft is said to 
reach a depth of 500 feet, and from the dumps it is evident that this 
is the most extensively developed property of the camp. From the 

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material on the dump some of the comitry rock appears to be rather 
coarser and more even grained than the normal pre-Potosi andesites 
and is probably an intrusive. Little definite information about the 
property could be had, but the mine contains some ore which is 
probably in the usual small, nonpersistent veinlets. The ore con- 
tains much sphalerite with galena and pyrite in a gangue of barite. 
Coatings of marcasite are common. As usual, the ore is associated 
with silicified country rock, with disseminated sphalerite and galena. 
Enargite was not recognized. It is said that $250,000 has been 
spent on the property, but that no ore has been produced. It is 
reported that the shafts could not be kept in alignment, owing to the 
movement of the groimd. This is very probable, as there is a large 
landslide mass just northeast of the mine and the adjustment is 
probably still taking place and extends to the shafts. 


The camp is above timber line and the heavy snows and long 
winters are unfavorable conditions. Excellent water is plentiful 
and there is abimdant spruce timber only a few miles away. Lake 
City, the nearest railroad point, is nearly 20 miles away, at an elevation 
about 3,500 feet lower; all supplies must be brought from that point 
and all the ore shipped from the camp was hauled there for shipment 
to the SaUda smelter. 


There seems little likelihood that large bodies of ore will ever be 
found at Carson, and whatever the camp produces will probably 
come from small bodies of rich ore. 


The ore deposits of Carson, Colo., occur in volcanic rocks of Ter- 
tiary age. Ilie oldest rocks near Carson are flows of andesite and 
quartz latite, belonging to the Silverton volcanic series. After a 
p^od of erosion there followed the formation of a complex of andes- 
ites and rhyolites of the Potosi volcanic series. At the base of this 
series are flows of rhyolite and quartz latite. Above these is a lens- 
like body of andesitic breccia with associated flows and iQtrusive 
rocks wtdch accumulated about an eruptive center at Carson. Flows 
of quartz latites and rhyolites, followed by andesitic rocks, covered 
up this acciunulation. The ore occiurs in gash veins within the pre- 
Potosi lavas and the intrusive rocks in the immediate neighborhood 
of the volcanic center. The country rock in the vicioity of the veins is 
everywhere much altered and is locally completely replaced by quartz 
and pyrite, although these minerals are not important constituents 

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of the vein filling. The chief yein minerals are barite, enargite, gale- 
nite, sphalerite, ohalcopyrite, pyrite, and marcasite. Barite and 
enargite seem to have been deposited first, followed by galenite and 
sphalerite, and finally by marcaaite. Pyrite continued throughout 
the early stages but is not abundant except in the wall rock. The 
values are chiefly in silver, with some gold and coppw, and in much 
of the ore they reach several hundred dollars to the ton. The ore 
was deposited in open spaces, few of which are completely fiUed, and 
is always associated with zones of decomposition in the poi^yry. 
It is in general not over a few inches thick, is not persistent, and is 
especially developed at cross fractures. Secondary enrichment has 
played an unimportant part. 

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By J. T. Pardm. 



The act inakmg i4)propriations for the sundry civil expenses of the 
Qoyemxaent for the fiscal year 1910-11 included an item providing 
for the mineral clasaification of certain lands within the limits of the 
Northern Pacific Railway Co.'s grant, for which title imder the 
original grant had been withheld pencUng such classification. The 
examination of these lands was assigned to the Geplogical Survey. A 
considerable area specified for classification is situated in northern 
Idaho, mainly in the drainage basin of upper St. Joe River, lying 
adjacent to and south of the Cceur d'Alene mining district. Three 
geologic parties and one topographic party spent a short and on some 
accounts unsatisfactory season in this particular area. Owing to the 
unexpected nature of the assignment, the work was late in starting, 
and on account of forest fires the season proved to be one of the most 
disastrous to life and property that has ever been known in this 
heavily timbered country. A considerable part of the area was 
reviewed, however, and the present report is a summaiy of the gen- 
eral evidence that has been collected. The map (PL II) is based on 
the control established by J. E. Blackburn, of the Geological Survey, 
and the geologic work is a compilation of the results obtained by 
F. C. Calkins and O. F. Loughlin in the area south of St. Joe River 
west of Avery; by D. F. MacDonald and E. L. Jones, jr., north of St. 
Joe River in a belt extending west from the valley of the North Fork; 
and by E. E. Smith and the writer in the upper St. Joe basin. The 
work as a whole was under the general charge of Hoyt S. Gale. 


Acknowledgments should be made to the Chicago, Milwaukee & 
Puget Sound Railway for location and right-of-way maps of its main 
Une within the area of the work, a preliminary location survey follow- 
ing upper St. Joe River, and topographic maps of a portion of the 


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Idaho-Montana boundary. A sketch map of the St. Joe drainage 
basin, by Con. Faircloth, a prospector, was also found useful. ''^^ 
descriptions of the different features of the area are taken 
unpublished reports of F. C. Calkins and D. F. MacDonald, in 
as they relate to their respective portions as defined above, 
microscopic determinations of rock sections used in this work 
made by Mr. Calkins. 


This region was described by Collier,* who made a reconnaisa 
within it in 1905, and neighboring areas have been described by 1 
gren * and by Ransome and Calkins.' 


Although this area is situated immediately south of the Cc 
d'Alene district and but a few miles west of the older Cedar Cn 
placer district, it has until recently remained in part almost unn 
plored. About 1873 prospectors crossing to the headwaters of t 
St. Joe from Cedar Creek discovered gold placer deposits that lie 
short distance southeast of this area and are said to be yet worked • 
some extent. During the excitement in the Coeur d'Alene district i 
1884-85 parties from that district penetrated the western portions i 
this area in an unsuccessful search for placers that was soon abai 
doned. After the completion of the Coeur d'Alene branch of th 
Northern Pacific Railway, in 1890, prospecting and development wori 
along the main divide was actively carried on, and since the recent , . 
opening of the St. Joe region by the Chicago, Milwaukee & Pugetc^^ 
Sound Railway interest in its mineral possibilities has revived. y 

GEOGRAPHY. ' ^ ,^ 


Except the highest summits and ridges, all of this area is or recently 
was clothed with a dense forest and denser underbrush. Bunch 
grass and other forage plants are abundant only in the nonforested " 
areas excepted. A small amount of forage is to be had in some of the 
old bums, chiefly on steep south slopes. A large percentage of this 
area is scarred with bums in various stages of reforestation. The 
fires of 1910 made a clean sweep of all that portion of the area north 
of St. Joe River and west of Bird Creek. Also practically the whole 
basin of the St. Joe above Simmons Creek was cleaned out, and of 
the remainder of this area about one-fourth was burned over. 

1 Collier. A. J.f Ore deposits In the St. Joe River basin, Idaho: Boll. IT. 8. Oeol. Surrey No. 286, 1905, 
pp. 12»-139. 

s LincIgrcD, Waldemar, A geological rpconnaissance across the Bitterroot Range and Clearwater Mountains 
In Montana and Idaho: Trot. Paper U. S. Geol. Survey Ko. 27, 1904. 

« Ransome, F. L., and Calkins, F. C, The geology and ore deposits of the Cceur d'Alene district, Idaho: 
Prot Paper U. S. Geol. Survey Na 02, 190& 

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General staiement. — ^This region as a whole is one of the least accessi- 
ble to be found within the United States, owing mainly to the topog- 
raphy and the forest cover. Except in those areas recently burned, 
the brush and litter render progress even by a man on foot very slow 
and laborious. Certain recently burned slopes were swept so clean, 
however, that they may for the present be readily traversed, but in 
most of the burned areas the fibre was accompanied or followed by 
extensive windfalls. 

Navigability of streams. — Canoes are poled against the swift water 
of the St. Joe as far up as Goddards, which is about 25 miles up the 
main river from Avery, and in short stretches above. It was also 
observed that attempts had been made to transport freight up and 
down stream in baizes by snubbing. Apparently these attempts 
had not been very successful owing to the rapid current and obstruc- 
tions in the channel. 

Conditian of highways. — Railroads, roads, and the principal trails 
are shown on the accompanying map (PL II). The road from Saltese 
to the Monitor mine is in good condition and is used for the hauling 
of ore and machinery. A road built preliminary to the construction 
of the Chicago, Milwaukee & Puget Sound Railway is still available 
for wagons from the St. Regis Valley to the North Fork of the St. Joe. 
The county road from Wallace to Hoyt, on St. Joe River, needs many 
repairs to make it passable for wagons. Of the few trails that pene- 
trate this region those within the recently burned areas are either 
temporarily blocked by windfalls or destroyed by slides. Some of 
the main trails are fairly good considering the rugged coimtry they 
traverse, but all have many steep and rocky pitches. The De Borgia 
trail is a fairly good one and is the most convenient means of access to 
the St. Joe at Conrads and above. Except for two steep spurs over 
which it zigzags, the trail from Avery to Goddards is not hard for pack 
animals, but its continuation east from Goddards is in poor condition. 
The principal trail leading south from Avery goes up Fish Hook Creek 
and along the west rim of this drainage basin to Sliderock Moimtain. 
From this point branches lead westward by which one may reach 
St. Joe and the mouth of Marble Creek. In 1910 the Marble Creek 
trail was in fairly good condition. The St. Joe trail, little of which 
was traversed, connects with numerous trails to homesteaders' cabins 
in Tps. 43 and 44 N., R. 3 E. The trail leading south from SUderock 
Mountain has branches leading eastward into Montana and one leading 
southwestward to Clarkia, Idaho, From Avery to the southern 
boundary of T. 44 N., R. 4 E., the trail is clear and in fair condition. 
The usual route to the east is that leading down the Little North Fork 
of the Clearwater, which in 1910 was clear in the surveyed area but 

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rough and boggy in many places. The trail leading northeastward 
from Forty-nine Meadows, though once a route of some importance, 
had not been used for several years and was much obstructed with 
windfalls, but a pack train was taken over it nearly to the eastern 
boundary of T. 44 N., R. 5 E. The trail to Clarkia was kept open and 
much used by firefighters and settlers during the fires of 1910. The 
trail over Lookout Moimtain has xmfortimately become disused and 
obstructed by windfalls, which necessitates a long detour and a drop 
and climb of about 1,000 feet that would be avoided if this cut-off 
were kept open. ''Mix's trail," at the southern border of the area 
investigated, is a short cut from the Clarkia trail to the Little North 
Fork. There are several trappers' and homesteaders' trails in Tps. 
44 and 45 N., R. 4 E., and T. 44 N., R. 6 E., which are not kept open 
so as to be usable by horses. 


The recent building of the Chicago, Milwaukee & Puget Sound 
Railway caused settlements to be made along its line — some of the 
evanescent type always linked with the construction of railways in a 
new region; others, like Avery, dependent on the railway's continuing 
operation. Away from the railway the only habitations are a few 
forest-ranger stations and miners' cabins, mainly near St. Joe River, 
and homesteaders' cabins in the drainage basins of Marble Creek and 
Clearwater River. 


Avery is a convenient outfitting point for prospectors and others 
desiring to explore the region to the south and west, or up St. Joe 
River as far as Goddards. Saltese and De Borgia, Mont., are the 
most convenient supply points for the area reached by the State line 
and De Borgia trails. In addition several smaller supply points lie 
along the railroad. 


Rdief. — Steep slopes characterize the surface of at least five-siaiJ ^ 
of this area. The remainder, of level or gently sloping ground, is 
foimd mainly on ridge summits or high rock-cut terraces. There is 
proportionately a small amount of level ground in the valleys of St. 
Joe River below Avery and upper North Fork. Elevations along 
St. Joe River are 2,300 feet at Big Creek, 2,500 feet at Avery, and 3,300 
feet at Conrads. The highest smnmits attain elevations of 6,500 to 
7,300 feet. In general the relief of the ridges separatiog the maia 
streams is 2,000 to 3,000 feet. 

Former baae-leveU. — ^The flats at approximately 6,000 feet elevation 
now forming the summits of ridges are apparently remnants of an 
extensive peneplain above which Wards Peak, the Three Sisters, and 

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other summits rise as monadnocks. Tliis peneplain is probably to be 
correlated with the extensive dissected plateau of the Clearwater 
Mountains ^ and with the level ridge summits exhibited in the CcBur 
d'Alene district to the north and beyond.' In addition, remnants of 
later but less extensive base-levels are found, the principal ones being 
at elevations of about 5,000 and 3,500 feet. 

MarUle. — ^The level and gently sloping surfaces are covered with a 
deep mantle and even the steeper slopes up to 32° bear an abundant 
soil held in place by the matting of vegetation. 

Rock exposures. — ^Below 6,000 feet elevation good rock exposures 
are found only on the cliffy slopes that border the larger streams. 
On the Montana side of the main divide the excellent continuous 
exposures contrast strikingly with the deeply mantled surface of the 
Idaho slope. The explanation of this contrast is found in the preva- 
lence of ice erosion during the last glacial epoch on the north and 
east slopes above elevations of 5,500 feet and its absence at corre- 
sponding elevations on the south and west slopes. 


Oharacter. — ^The intricate drainage system of St. Joe River is evi- 
dently inherited from the former base-levels, upon which the streams 
flowed in sluggish winding courses. The main stream and its largest 
tributaries exhibit sets of meanders that are remarkable when their 
deep intrenchment in the solid rock is considered. The stream pro- 
files are moderately steep, St. Joe River having an average grade of 
20 to 30 feet to the mile. Its larger tributaries maintain similar 
grades well toward their heads. 

Waier power. — Owing to favorable natural conditions a great 
amount of power could be obtained from these streams without 
undue expense for the construction of plants. As an instance, a 
particularly favorable power site was noted at an oxbow of St. Joe 
River about half a mile below Conrads. There the river falls 60 feet 
while rounding the included promontory, whose nock or isthmus is 
but 800 feet through. Conditions here also favor the obtaining of 
additional head by damming. 



Most of the sedimentary rocks of this area are considered to be the 
equivalents of the Algonkian formations of the Ccenr d' Alene district.' 
They are briefly described as follows: 

I Lindgzien, Waldemar, op. cit.^ p. 50. 

s Ranaome, F. !»., and Calkins, F. C, op. dt., p. 76. 

sid«ia,pp. 26«tnq. 

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Generalized tabtUar iection of sedimentary rocks in the St. Joe River basin. 





High bench gravels. 

Algonklan (Belt 

Striped Peakformatioii. 

Light-gray to greenish flaggy sandstones, gnywaokes, and 


Probable eqaivalant of 
upper part of New- 
land ("Vallaoe") «wv 

greenish shale. 

Probable equivalents of 
lower pgft of New- 
land (''Wallace") for- 
mation and upper part 
of St. Regis formation. 

Palefreeniah, indistinctly banded shale with thin inter- 
bedded layers of sandstone, probably equivalent in pan 
to the St. Regis, overlahi by nay, {bin-bedded, digStly 
sericitio, white-weathering sandstones, with which are in- 
terbedded considerable amounts of bnfl-weathering gray- 
banded argilllte, greenish limy shales, and blue to gray 
limestone. In the metamorphosed areas all these shales 
are altered to pale-greenish and chocolate-brown horn- 
stones, which are, in many places, studded with white 
grains of scapolite about the size of buckshot. 

Probable equivalents of 
tbe Burke and Revett 
formations and the 
lower part of the St. 
Regis formation. 

White, rather flaegy, slightly serlcitlc quartzites, grading 
into grayish andbrownbh quarUltes and schists. 

Prichard formation (pos- 
sibly including some 
older beds). 

tiated on the map), overlain bv about 1,000 feet of pare 
thick-bedded quartzites, and tnesa in turn by gray and 
brown mica schists. 


The rocks assigned to the Prichard formation in this area differ 
from the typical Prichard formation of the Coeur d'Alene district in 
containing thick strata of pure quartzite. It is not known, however 
whether these quartzites are lower than any beds in the Coeur d' Alene 
section or represent a horizontal variation. The dominant rock here 
is mica schist, instead of slate, as in the Coeur d'Alene district, but 
this is due to the strong metamorphism that prevails in the parts of 
the region where the formation occurs. 

The supposed equivalent of the Revett quartzite is more micaceous 
and thinner bedded here than in the type locaUty and therefore less 
distinct from the beds which are believed to represent the Burke 

The beds which are beUeved to represent the Newland ("Wallace") 
formation are apparently much thicker than that formation in the 
Coeur d'Alene district, and toward the southeast they show a propor- 
tionately greater development of sandstones. The white and gritty 
weathered surfaces of these sandstones also generally show red and 
yellow specks of iron oxides. The characteristic purplish bands of 
the St. Regis formation are here lacking. The strata representing 
the upper part of the Newland ("Wallace") and the Striped Peak 

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axe like those formations in the CoBur d'Alene district, except that 
the equivalents of the Striped Peak show fewer reddish bands. The 
high bench gravels are found mainly west of Avery, as shown on the 
m^). In addition there are a few very small patches adjacent to 
th« river above Avery. These gravels lie on the base level at 3,500 
feet and are thought to be equivalent in age to similar gravels in the 
Prichard Creek district and other parts of the CcBur d'Alene region. 
In this area, however, they are not gold bearing so far as known. 


Forms suggestive of organic origin were found at two horizons 
in the beds representing the Newland ("Wallace'') formation. The 
lower horizon is about 1,000 feet above that of the Wishards sill and 
the upper about 1,000 feet above this. On the summit of Quarles 
Peak the lower horizon is represented by a bed of grayish limy shale 
about 3 feet thick, crowded with flattened globular forms from half 
an inch to an inch in diameter that suggest bivalves of some sort. 

The locahties at which observations were made at the upper hori- 
zons are three-fourths of a mile southwest of the summit of Quarles 
Peak and in rock cuts along the line of the Chicago, Milwaukee & 
Puget Sound Railway about half a mile below the Adair loop (sta- 
tion 395 + 50 west of East Portal) and about 2 miles above the loop 
(station 243 + 50 west of East Portal). At these localities a bed of 
bluish limy shale or impure limestone contains numerous flattened 
cylindrical forms resembling mashed trilobites. Dr. Walcott has 
examined the specimens brought in from the field and states that 
they ''are elongated, more or less corrugated calcareous nodules, and 
some of them suggest oi^anic origin." 


Granitoid gneiss. — The gneiss intercalated with the schists near 
the base of the section is chiefly a gray, strongly laminated rock of 
medium-coarse granular texture modified by reciystalUzation under 
great pressure. The chief constituents are soda-lime feldspar (oligo- 
clase), quartz, orthoclase and microcline much inferior in amount to 
the oligoclase, biotite, and epidote, locally with more or less horn- 

Anorihosite. — In the southern part of T. 43 N., R. 4 E., is a large 
area of whitish rock consisting essentially of soda-lime feldspar with 
the average composition of labradorite. This anorthosite shows no 
very conspicuous evidence of pressure except in local phases that 
contain small amoimts of hornblende and other dark minerals which 
are drawn out into streaks and give the rock a gneissoid banding. 
Microscopic sections of the more purely f eldspathic variety, however, 

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show it to have been thoroughly crushed and sheared. It has suf- 
fered, m fact, about the same amount of d3rnamic metainorphism as 
the gneiss above described. 

PegmcOUes. — ^P^matites that form numerous and conspicuous 
dikes and sheets in the gneisses and schists of T. 43 N., K. 4 E., con- 
sist chiefly of orthoclase and quartz, and most of tbem contain small 
amounts of mica and of soda feldspar. Their most interesting fea^ 
ture is the great variation in the amount of the quartz. Gradations 
can be traced from pegmatites with quartz subordinate to feldspar 
into those composed almost wholly of quartz; and it is probable that 
many quartz veins free from feldspar in the area where pegmatites 
are abimdant are of magmatic origin. 

Granodiorite. — ^In the southern part of the territory examined are 
two areas of granitoid rock evidently much younger than the strongly 
foliated intrusive rocks described, for while they occur in close prox- 
imity to these rocks, they are not appreciably sheared. They pre- 
sumably represent part of a vast intrusion which occupies himdreds 
of square miles to the south ^ and which has probably caused the 
greater part of the contact metamorphism observed south of St. Joe 

The rocks of the two areas are very similar and remarkably uni- 
form. They are of medium granular texture, and consist essentially 
of plagioclase (andesine and oligoclase), subordinate orthoclase, 
quartz, and biotite, locally with a httle hornblende. 

A few small dikes of granodiorite porphyry cut the strata represent- 
ing the Newland C Wallace") formation in the vicinity of St. Joe 
River a short distance above Avery. This rock shows abundant 
phenocrysts of white feldspar and altered biotite and hornblende in 
a pale-greenish groundmass. 

Porphyritic momonite of Black Prince Creek, — ^The iutrusion crossed 
by Black Prince Creek and the neighboring smaller intrusions show 
much variation but consist chiefly of a porphyritic monzonite con- 
tainiQg abundant large phenocrysts of microcline in a groundmass 
about as coarse as average granite and composed essentially of plagio- 
clase, microcline, quartz, biotite, and hornblende. The quartz is in 
rather small amount. The rock has been much fissured and affected 
by innumerable small faults along curved slickensided surfaces that 
are weU exposed in railway cMttings. The chief interest of this mon- 
zonite hes in its marked resemblance to the dominant rock in the 
intrusions of the CoBur d'Alene district. This resemblance is signifi- 
cant in view of the evidence that the monzonites of the CoBur d'Alene 
district have been concerned in the mineralization of that richly pro- 
ductive area.^ 

1 LtaidgroD, Wtldemar, op. dt., p. 17. 

3 Ransome 7. L., and Calkiiu, F. C, op. oit., pp. 135 et seq. 

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CampUmiU. — ^A few dikes of eamptonite with north-south course 
cut the strata representing the Newiand (''Wallace") formation on 
the spur west of Maylan Creek. It is a light greenish gray rock 
showing slender prisms of hornblende in a feldspathic groimdmass 
similar to some north-south dikes in the CoBur d'Alene district. 


Wisharda «ifl. — ^A striking lithologic feature of this area is a thick 
and persistent diabase sill intruded near the middle of the strata rep- 
resenting the Newiand ("Wallace'') formation. A prominent knob 
of the Idaho-Montana divide near milepoet 153, known as Wishards 
Peak, is formed from this rock, hence the name Wishards sill may be 
appropriately applied to it. From this point it outcrops in a narrow 
band that closely parallels the divide to the St. Paul tunnel of the 
Chicago, Milwaukee & Puget Sound Railway and beyond. In the 
opposite direction to the southeast its outcrop continues toward St. 
Joe River, leaving the divide at Wishards Peak. Again, from God- 
dards to Maylan Creek the sill forms picturesque cliffs and knobs, 
set slightly back from the river's south bank. The river channd 
from Conrads down to (Soddards is a narrow gorge cut in this rock. 
Seen at a distance, outcrops of this rock appear nearly black; at close 
range they are dark rusty greenish and on fresh fracture dark dull 
green in color. In texture the Wishards sill varies from that of a 
basalt at its margin to that of a characteristic diabase, showing to 
the imaided eye white feldspar laths embedded in a dark-greenish 
ciystaUine groundmass of the ferromagnesian minerals. Locally its 
texture is coarse like that of a gabbro. The microscope shows it 
to be of a rather siliceous type, free from oUvine, and composed 
essmitially of labradorite, augite, ilmenite, and interstitial micro- 

Offter siUe and dikes. — ^Diabase essentially similar to that of the 
Wishards sill forms many smaller sills and dikes in the strata repre- 
senting the Newiand ("Wallace") and underlying formations. The 
largest of these basic intrusions below the Wishards sill, in T. 43 N., 
R. 4 E., is shown on the map. It forms a thick lenticular mass in 
the upper part of the schists correlated with the Prichard formation. 
It extends east of the area examined, and the dark and jagged Monu- 
mental Peaks f^pear from a distance to be carved from the same 

The diabase has suffered contact metamorphism together with the 
intruded sediments, and where the sediments have been altered to 
coarse mica schists the diabases have been altered to schistose 

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The basalt caps shown on the map (PL II, p. 40) are remnants of a 
comparatively recent lava flow, presumably to be correlated with the 
great Tertiary lava floods of the Columbia basin. 



Pdcksaddle syndine. — ^The most prominent structural feature of 
this area is a large, open, fairly symmetrical syncline whose axis 
trends about N. 65° W. The position of its axis is shown by small 
areas of the Striped Peak formation lying between Packsaddle Moun- 
tain and Striped Peak. It will be referred to as the Packsaddle 
syncline. The trough involves an area roughly 5 miles wide and 20 
mUes long ending to the southeast in canoe form near Bird Creek and 
to the northwest in a somewhat similar manner. 

Other folds. — ^Another fold that may be commensurate with the 
Packsaddle syncline is an anticline shown by the plotted dips south 
of Lookout Mountain in T. 43 N., R. 4 E. There was no oppor- 
tunity to detenniue its full extent, but it is known to persist for at 
least 5 miles. It is complicated, as the Marble Creek section shows, 
by minor folds and has an eastward pitch, which also characterizes 
the numerous other less persistent folds in the southwestern part of 
the area examined. Small compressed pitching folds whose axes 
vary in trend but as a rule course west-northwest are characteristic 
of the area lying between St. Joe River and the most northeasterly 
outcrops of the Wishards siQ, except the portion occupied by the 
Packsaddle syncline. Except in a small flexure trending northwest 
through Wards Peak the area northeast of the sill outcrop mentioned 
exhibits moderate southwest dips only. On the other hand, north- 
east dips prevail in the area southwest of the Packsaddle syncline, 
hence the structure of this area as a whole may be perhaps defined 
as that of a northwestward-trending geosyncline succeeded to the 
south by an anticline. 


Steeply inclined faults exhibiting the dominant northwesterly 
trend are numerous in the areas of complex folds. They are in many 
places but not everywhere accompanied by thick breccias. The 
course of St. Joe River from Avery up to Conrads seems to have 
accommodated itself somewhat to a zone of faults, some of which 
have caused considerable displacement. Of these, the St. Joe fault, 
having a downthrow to the north of at least 1,600 feet, brings up the 

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V^hards sill south of the river, and the Skookum f aiilt drops the blue 
shales which represent the upper part of the Newland (''Wallace'') 
formation against the middle beds of that formation. This fault is 
accompanied by a breccia in places 300 feet wide. 

There is a great fault of west-northwest trend that follows the 
general course of St. Joe Eiver near the mouths of Marble and Mica 
creeks. Its downthrow is on the north and is great enough to bring 
the strata representing the Newland formation into close proximity 
to the quartzites far down in the Prichard. 

The distribution of the rocks near the boimdary of Tps. 44 and 45 
N., R. 4 E, is hardly explainable without much faulting, but the 
exposures here are so poor that it is doubtful whether the structure 
could ever be satisfactorily deciphered. There is strong evidence of 
the existence of a fault or fault zone with downthrow to the south, 
following the general course of Boulder Creek. Brecciation has been 
observed in the quartzites both north and south of that stream. 

A great fault of nearly north-south trend has been found in the 
southern part of the Fish Hook basin. Its throw must amount to 
thousands of feet, for it brings rocks representing the Newland on 
the west against beds several thousand feet below the top of the 
Prichard formation. 


2jones in which the rocks are sheared and crushed are nxmierous in 
the areas of complex folds. These zones are not well defined and 
can not be exactly bounded, and the degree of crushing or shearing 
in them is variant, but areas in which the quartzitic rocks are crushed 
to the semblance of a breccia may be from a few himdred feet up to a 
mile or more across. The shaly beds of the Newland (** Wallace") 
and the diabase intrusions are commonly sheared. 


The sedimentary rocks and the older intrusive rocks are strongly 
metamorphosed in about half of the area examined. The intensity 
of the metamorphism is least toward the northeast and increases 
toward the west and south. A distinction is to be made between the 
thermal metamorphism due to the monzonitic intrusions exposed 
near Copper Prince and the much more intense metamorphism, 
partly thermal and partly dynamic, chiefly developed in the southern 
part of the area, prestunably due in the main to a huge batholith that 
occupies great areas to the south of the territory here considered and 
is probably represented by the nonfoliated granite found at the head 
of the Clearwater. It is doubtless due in part also to the old granites, 
anorthosites, and diabases (pp. 44-46), now altered to gneiss and am- 

94174**— Bull. 470—11 4 

Digitized by 



phibolite, but these have suffered more metamorphism than they have 
caused. The diabase, where it occurs apart from other intrusive 
rocks, can be seen to have caused relatively slight metamorphism. 

The metamorphic effect of the monzonites is first perceived on 
going down the railway from Avery, near the mouth of Slate Creek, 
where the buff-weathering blue and gray Newland beds grade into 
hard fine-grained homstones coarsely banded and mottled in pale 
green and chocolate-brown. While the metamorphic nature of these 
rocks is not very evident to the impracticed eye, and their general 
appearance faintly suggests that of the St. Regis formation, micro- 
scopic study shows the brown layers to be rich in biotite and the 
green layers rich in pyroxene and amphibole and proves that they 
are metamorphosed calcareous sediments. Farther on the shaly 
beds of the lower formations are represented by mica schists even 
more clearly showing the effect of contact metamorphism. 

Near the wes.' 'm limit of the area the metamorphism due to the 
monzonites merges with that of other origin. At the east, however, 
the monzonite has had no effect and the increase of metamorphism 
toward the south can be clearly observed. In the vicinity of the 
State line and Packsaddle Mountain a very slight metamoiphism is 
shown by a faint brownish banding only in some argillites. Toward 
the river some of the sandy shales gradually become micaceous, 
resembling schists, and the argillites grade into greenish and 
chocolate-brown homstones, the latter thickly studded with round 
grains of scapolite that stand out on weathered surfaces suggesting 
so many white fish eggs. 

The metamorphism in its extreme degree is best observed in T. 43 
N., K. 4 E. The general aspect of the old sediments and intercalated 
intrusive rocks is such that they woidd probably be assigned to the 
Archean were it not that they are conformable with the overlying 
Algonkian. The quartzites are coarsen^ by recrystallization and 
the less pure beds contain conspicuous crystids of garnet or cyanite. 
The argillaceous beds are represented by coarse mica schists, garnet- 
iferous for the most part, some of the garnets in which are nearly as 
large as a tennis ball. Pegmatitic material permeates these rocks 
very intimately in the form of minute veins or lenses parallel to the 
bedding, and even in isolated feldspar crystals. The rocks where 
this material is abundant are properly characterized as injection 
gneisses. The foliation of the granitoid gneisses and sheared anor- 
thosite shows most clearly how large a part pressure as well as heat 
has played in the metamorphism. Of all the igneous rocks, the 
diabases have suffered the most radical change of texture and mineral 
constitution. Where metamorphism is thorough, the diabase is 
altered to a black schistose amphiboUte studded with red garnets. 

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Mineralization of the country rock by the introduction of specks 
or grains of such minerals as pyrite, chalcopyrite, and siderite is 
found in certain formations or under certain conditions. The most 
noteworthy example of this is the occurrence of grains of siderite 
(spathic iron) generally disseminated in the sandstones of the strata 
representing the lower part of the Newland ("Wallace") formation. 
Siderite is somewhat more sparingly present in the sandy shales also. 
This phenomenon is most characteristic of the areas of complex 
structure. This mineral replaces other constituents of the rock in a 
way similar to the mode of its occurrence in the Coeur d'Alene dis- 
trict, where, however, it is found in the Burke and Revett quartzites 
instead of in the Newland ("Wallace") formation. The bluish- 
greenish shales and slate which represent the upper part of the New- 
land formation show little or no general mineralization except a 
sparing distribution of pyrite in some areas. The strata representing 
the Burke and Revett formations and the lower quartzites and 
schists contain specks and crystals of pyrite more or less generally 
disseminated, and in small areas a little chalcopyrite. 


Lodes, — ^Lodes of the more or less pockety or replacement type are 
numerous in certain areas, mainly those occupied by the strata rep- 
resenting the lower part of the Newland formation. All the lodes 
contain chalcopyrite and pyrite as the chief or among the chief ore 
minerals. Galena and sphalerite are found in a small area. Siderite 
is the chief gangue mineral in most of the lodes; quartz and calcite 
in others. 

FavU breccias and crushed zones. — Crushed zones and fault breccias 
found in the sandstones of the Newland formation are usually 
cemented to a greater or less extent by siderite and some calcite. 

Sheared zones. — Sheared zones in the diabase are generally mineral- 
ized by the introduction of calcite, quartz, and siderite that form 
"knife-blade" seams or veinlets and irregular bunches, and by the 
introduction also of varying amounts of pyrite and chalcopyrite. 


Some reported assay values are given in the descriptions of the 
prospects, from which it appears that the lodes containing pyrite and 
chalcopyrite carry up to $10 or more to the ton in gold and a little 
silver. In addition assays of samples ^ collected in the field indi- 

t Thew samples wore assayed for gold and silver at the United States assay offioe, Helena, Mont. 

Digitized by 



cate that in general the outcrops of the large sideritic lodes contain 
traces of gold and a little silver, usually less than 1 ounce to the ton, 
and that outcrops of the sheared zones in diabase showing '^ knife- 
blade" seams of quartz or calcite contain from traces up to $3.60 to 
the ton in gold, from traces up to 4 ounces of silver to the ton, and 
traces (less than 0.1 per cent) of copper.* Assays of the lodes show- 
ing galena, chalcopyrite, or pyrite other than the reported ones 
referred to are not at this time available. 


For the comparison of the mineralization and general geology this 
area may be conveniently subdivided into four portions. These por- 
tions can not be exactly bounded, but their location and approximate 
limits and their chief characteristics may be given^ as follows: 

iThe detennlnatlon o£ copper in these sampleB was made by the laboratary of the United States Geo- 
logical Survey. 

Digitized by 

















JS oS 00 w 





Digitized by 




In the St. Joe and Black Prince Creek areas is found the combina- 
tion of factors most favorable to ore deposition and of evidences that 
such deposits occur. Thorough prospecting of these two areas is 
certainly warranted by the favorable conditions of structure, degree 
of metamorphism, and general and special mineralization. So far 
as the evidence at hand goes, the chief values are to be expected in 
gold and copper. Considerable promise is held out by many of the 
better-defined lodes. That portions of the mineralized shear zones 
in diabase may be found to constitute low-grade ore is indicated 
by the few assays available. Increase of values in depth should in 
general not be expected, for it appears that oxidation of the lodes 
and shear zones has reached a slight depth only and that secondary 
enrichment is absent. The Slate Creek area, however, in addition to 
generally scant evidences of mineralization, is structurally unfavor- 
able for ore deposits. The Sliderock Mountain area shows generally 
a too intense metamorphism and too few direct evidences of minerali- 
zation to be considered favorable for ore deposits. It appears as if 
erosion has planed away all but the roots of the lodes that had been 
developed in this area. While for these two areas the general con- 
clusion is drawn that they are unfavorable for ore deposits, it must 
not be construed to mean that they contain no ore deposits whatever 
or that none of the prospects already located will develop into paying 



^ati, — ^The Ward mine is situated on the southeast spur of Wards 
Peak, near milepost 161 of the Idaho-Montana boundary, and lies 
within the two States. It is one of a group of claims lying mostly 
in Montana, the others of which were not visited. It is developed 
by an adit level and drifts aggregating 1,200 feet in length, a shaft 
80 feet deep, and some minor openings. The country rock is pale 
greenish banded shale with thin quartzite beds, representing the 
lower part of the Newland (*' Wallace") formation. A vertical 
diabase dike of irregular width trending about N. 75^ W. cuts the 
shales. A mineralized shear zone 50 feet or more wide trending 
west-northwest affects the diabase principally. Within it are 
numerous seams and veins of quartz, calcite, and siderite, carrying 
small amounts of chalcopyrite, pyrite, and chalcocite. Specks of the 
chalcopyrite and pyrite have been also introduced along the innumer- 
able shearing planes of the zone, and the whole mass is said to assay 

I This and the foUowing sabdlvlaions are defined In the tabular summary on page 53. 

Digitized by 



S4 and more to the ton in gold. At the time of visit a few tons of 
this ore was being shipped to a smelter as a test sample. 

Jfonitor. — ^The principal mines adjacent to and on the Idaho side 
of the State line are the Monitor, Richmond, and others in the midst 
of a large group of claims lying between the divide and the loop of 
the Chicago, Milwaukee & Puget Sound Railway. Considerable 
development work was done on tiie two claims mentioned, but their 
hoists and other improvements were completely destroyed by the 
forest fires of 1910, and they were for the time being inaccessible. 
These deposits are all in limy and shaly sandstones representing the 
lower part of the Newland C* Wallace") formation, near the horizon 
of the Wishards sill. From the mine dumps it appears that the upper 
workmgs are in oxidized material, carrying large percentages of iron 
and some copper carbonates. In depth this is succeeded by chal- 
copyrite and pyrite in a gangue consisting mainly of calcite and 

Big EOc. — ^The Big Elk prospect, located just above the Chicago, 
Milwaukee & Puget Sound Railway tracks, about 2 miles northwest 
of Adair, was seen before the fires reached that vicinity. This is a 
replacement along a shear zone that can be traced for half a mile or 
more, trending N. 40** to 70® W. in the lower part of the sandy shales 
regarded as belonging to the Newland formation. It is developed 
by a 40-foot shaft, a 15-foot winze, and some short adits. The shear 
zone has been mineralized up to 6 feet in width by the introduction of 
chalcopyrite, pyrite, calcite, and quartz. Within this mineralized 
portion are found irregular bunches up to 2 or 3 feet thick of chal- 
oopyrite with a calcite and quartz gangue. This ore is said to assay $ 10 
in gold and 2 or 3 ounces of silver to the ton and 30 per cent of copper. 

Silica. — ^A quarter of a mile north of the north Une of sec. 6, T. 46 N.^ 
R. 6 E., the Silica Gold & Copper Mining Co. has a group of claims 
located on three parallel veins, which cut limy, buff-weathering sedi- 
ments representing the Newland formation. The chief lode seems 
to consist of a fault zone which is 6 feet or more in width and is filled 
with crushed rock and more or less angular fragments of quartz. It 
trends about N. 70® W. and may be a continuation of the faulting 
ahown on the railroad cut in the southern part of sec. 4. A few little 
local bunches of pyrite and chalcopjrrite occur, apparently where side 
fissures intersect the main brecciated zone. The sulphides are said to 
carry gold to the value of $4 to $12 a ton. Siderite and calcite also 
occur in varying amounts. The so-called middle lode is 150 feet 
north of the one just described and roughly parallel to it. The de- 
velopment work consists of an open cut 20 feet long which shows a 
great siderite lode approximately 20 feet wide, trending S. 80® E. 
and dipping steeply south. No pyrite or chalcopyrite was observed 
here. About 1,200 feet north of this lode occurs another almost pai^ 

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allel vein. It consists of a shear zone in siliceous sediments repre- 
senting the Newland formation, where quartz has replaced some of 
the crushed country rock. No other mineralization was observed here, 
although it is said that specimens of auriferous pyrite and chalcopy- 
rite had been found in the vein. 

Si. Joe Qttartz and vicinity. — ^At the prospects located along St. Joe 
River the most development work has been done on a claim at God- 
dards owned by the St. Joe Quartz Mining Co. A tunnel 400 feet long 
penetrates a mineralized shear zone in the Wishards sill. The zone 
trends about east and west and contains irregular seams and bunches 
up to 3 feet wide of quartz, calcite, and chalcopyrite. A few tons of 
of the ore had been sacked and piled on the river banks. Half a mile 
above this a short adit on the Black Bear claim exposes a 4-foot vein 
striking N. 85° W. and consisting chiefly of scapolite with relatively 
small amounts of sodic plagioclase, calcite, epidote, and garnet. It 
contains an irregular streak of partly oxidized pyrite a few inches 
thick and is separated into two unequal layers by a 6-inch parting of 
diabase. The vein is vertical and has one sUckensided gouge-lined 
wall upon which post-mineral faulting has occurred. The diabase 
is well exposed here and contains many shear zoiies. These are more 
or less mineralized, usually showing veinlets of quartz and calcite and 
the green stain of copper carbonates. 

Eureka. — Half a mile to the east of Goddards a location by Isaac 
Hegarty is based on a persistent quartz outcrop trending N. 68° W. 
This lode is in metamorphosed sandstones representing the lower part 
of the Newland ("Wallace") formation and is apparently a replace- 
ment along a crushed zone. It varies from 1 to 10 feet in width and 
consists of massive white quartz together with heavily ferruginous 
porous quartz and some undecomposed siderite and pyrite. 

Conrad's crossing. — In the vicinity of CJonrad's crossing on St. Joe 
River a few short adits and trenches have been made on small veins 
that are numerous in the diabase. The country rock is severely 
sheared and more or less mineralized in many places. The minerali- 
zation consists in the introduction of minute crystals of chalcopjrrite 
and pyrite along shear planes, and the development of seams and 
irregular bunches up to 3 feet or more wide of calcite, quartz, and 
siderite carrying chalcopyrite and pyrite. The green stain of copper 
carbonate may be seen at many places on weathered surfaces of the 

Alice. — Some locations about a quarter of a mile east of the mouth 
of Bird Creek are known as the Alice group. Here an extensive re- 
placement deposit occurs along a shear zone in the middle part of the 
quartzites regarded as belonging to the Newland ("Wallace") for- 
mation. It is developed by a 70-foot adit which shows the following 

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Section in adit of Alice group. 

Ft. in. 

Ocber 6 

Vein quartz containing pyrite 1 

Qnartzite ^ 1 

Ocher 6 

GniBhed quartzitic shale containing much calcite 21 

Ocher 6 

Calcite and siderite with some pyrite 30 

Ocher 6 

The strike of the several layers here is N. 50® W. and the dip 

Blue Bird, — On Blue Bird Creek near the southeast comer of 
T. 46 N., R. 6 E,, a recent discovery known as the Blue Bird claim 
was being developed at the time of visit. The shallow discovery pit 
was about 8 feet square and located in the bottom of the canyon at 
the stream level. The top of a lode or pocket of quartz and calcite 
carrying considerable chalcopyrite and pyrite was exposed, occupying 
the whole pit. However, development had not proceeded far enough 
to show its thickness. The country rock consists of bluish and grayish 
sandy shales near the upper part of the strata representing the New* 
land (''Wallace") formation. 


Along the State line from Wards Peak northwestward on the 
Montana slope are a number of mines and prospects reported as 
valuable and promising, such as the Bald Moimtain, St. Lawrence, 
Buffalo, and Wishard. They were not visited for lack of time. 


Oiyjpfer Prince. — ^The most promising prospect so far shown in the 
metamorphosed strata representing the lower part of the Newland 
("Wallace") formation is the Copper Prince, near the mouth of Black 
Prince Oeek. It is situated in sec. 10, T. 45 N., R. 3 E., 800 feet 
south of sec. 3, but its trend may bring it within this section, though 
it can not at present be traced there because of the mantle of surface 
debris. Toward the east it is traceable across the line into sec. 11 
and there is lost under the surface soil. Altogether it can be followed « 
for nearly a third of a mile. The (popper Prince lode trends about 
N. 70° W. and is nearly vertical. It is a series of parallel slopes in 
highly metamorphosed shales representing either the Newland 
('< Wallace") formation or the St. Regis formation and is in close 
proximity to intruded masses of granitic and monzonitic rocks, aplite, 
and diabase dikes. The chief minerals are pyrite and chalcopyrite, 
with siderite, quartz, and calcite, and these occxu" in small fissures 
and joints and in little irregular bunches replacing the country rock. 

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This scattered and bunchy replacement type is characteristic of the 
lode so far as developed near the mouth of Black Prince Creek, but 
1,000 feet north of this it seems to be better defined and to show a 
shear zone 4 to 5 feet wide filled with quartz, which has largely replaced 
the crushed material and some of the wall rock. Here, however, the 
evidence of mineralization is not very pronounced. About 100 feet 
still farther west a 10-foot tunnel shows the lode to be 3 feet wide, 
fairly well defined, filled with crushed, iron-stained country rock and 
quartz, and giving much more evidence of a possible definite ore body 
than it does farther to the east. The development work, in addition 
to the short tunnels and few small open cuts on the west end of the 
outcrop, consists of three tunnels — one on the west side of Black 
Prince Creek, 60 feet; another on the east side, 75 feet; and a third 
just over the line in sec. 11, driven in 40 feet deep. In some places 
the lode is wholly in sedimentary beds and in others it occurs as a 
shear zone between the sediments and the intrusive rocks. It seems 
to show local changes of direction, possibly due to intersecting side 
fissures, and such intersections might reasonably be expected to 
contain ore bodies. 

Kelly. — ^Near the contact of the Prichard formation with the over- 
lying quartzite along the railway a mile east of Marble Creek, a pros- 
pect is mapped (PI. II). This location, made by Kelly Bros., of 
Avery, is on a branch vein which shows a maximum width of 12 
inches and pinches out above. It suggests a quartz differentiation 
from or an end product of an apUte dike. Some postmineral shearing 
has occurred along its walls. The vein is filled with quartz, some- 
what stained with iron and a trace of manganese oxide, and contains 
pyrite and chalcopyrite. Small stringer veins, aplite dikes, and a few 
shear zones occur in this formation and all carry a little pyrite with 
a few crystals of chalcopyrite. 

TheriauU. — Another prospect which gives some promise is that 
located by E. I. Theriault in strata believed to represent the basal 
part of the St. Regis formation. Here a diabase dike trending N. 65** 
W. and dipping 76^ S., about 2 feet wide, has been sheared and well 
mineralized. The pyrite in it is said to carry gold values to the extent 
of <3 to $10 a ton. The gangue is principaUy quartz and iron-stained 
dike rock. The vein averages about 10 inches in width and has been 
exposed by open cuts both below and above the railroad track. 
Close to this lode and more or less paraUel with it are other smaller 
and less important shear zones, which show more or less minerali- 
zation. The metamorphosing influence of the granitic intrusive 
rocks can be detected almost as far east as Slate Creek and is shown in 
the aplite dikes, quartz stringers, local areas which carry pyrite and 
some chalcopyrite crystals, iron-stained, metamorphosed-looking 
shear zones, and irregular bunches of calcite. 

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Floodwood Creek. — A prospect that shows eyidence of valuable 
mineralization is at the head of Floodwood Creek, near the center of 
sec. 27, T. 43 N., R. 4 E. The country rock is a crumpled injection 
gneiss composed of alternating thin layers of dark mica schist and 
white pegmatite. The average strike is northwesterly and the dip 
northward at moderate angles. The development consists of a tunnel 
about 35 feet long, an open cut about 30 feet long and 10 feet deep, 
and some other small open cuts that show nothing of interest. The 
direction of the tunnel appears to have been ill calculated, for it 
crosses at an acute angle a vein which appears just beside the portal 
and, so far as observed, it taps no others. This vein is about 6 inches 
thick, is nearly parallel to the bedding, has a quartz gangue, and con- 
tains a small proportion of chalcopyrite and probably other minerals 
in particles too small for identification. 

More conspicuous indications appear in the largest open cut. 
This shows no well-defined persistent vein but rather a number of 
groups of small veins nearly parallel to the bedding. There are two 
principal groups. One, about 2 feet in aggregate breadth, is composed 
of several rather poorly-defined veins with a maximum thickness of 
about 3 inches. Another, about 5 feet from this, consists of two veins 
each 1 foot to 2 feet thick, divided by thin partings. All the veins seem 
more or less lenticular and uneven in thickness. The composition is 
similar to that of the vein at the tunnel. 

Collier * quotes a report that an average sample taken across the 
ledge yielded $2.48 in gold, silver, copper, and lead and states that 
a picked sample was found to contain a trace of gold, 0.8 ounce of 
silver, and 2.1 per cent of copper. No further assays are at present 

Fish Hook Greek,— Or Fish Hook Creek, in T. 45 N., R. 5 E., about 
half a mile north of the point where the trail leaves the stream, there 
is a shallow opening on a quartz vein 2 feet thick, parallel to the bed- 
ding of the country rock (representing the Newland formation), 
which dips 35** N. The quartz contains rusty hollows from which 
pyrite or some other sulphide has probably been leached. 

Large quartz outcrops. — ^In the southern part of this area there are 
numerous quartz veins, some of which attain a thickness of several 
feet. Many are remarkable for the purity and whiteness of the quartz 
composing them; others are discolored to a sUght extent by decomposed 
pyrite. Farther north veins are less commonly seen, owing in part 
no doubt to the general poverty of the exposures. The largest vein 
seen cutting the strata representing the Newland formation is one of 

^Collier, A. J., BuU. U. S. Oeol. Survey No. 285, 1006, p. 136. 

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quartz near the head of Siwash Creek, in T. 44 N., R. 5 E. It forms 
a bold outcrop about 50 by 20 feet in extent, elongated in an east- 
west direction, but it does not seem persistent. 


SUver Spray, — ^In sec. 11, T. 46 N., R. 4 E., is the Silver Spray pros- 
pect, which consists of two tunnels and several open cuts. Tunnel 
A bears about N. 24° W. and enters 700 feet from the mouth of Pros- 
pect Creek. It has been driven 58 feet into bluish slates representing 
the upper part of the Newland ("Wallace") formation, which are 
here interbedded with some buff-weathering to Ught-gray fine- 
grained shales and quartzite beds. The mineralization occurs in a 
quartzite bed IJ to 2^ feet thick, which dips 10® N. and consists of 
siderite, pyrite, crystals of chalcopyrite, galena, a Uttle micaceous 
hematite, and some zinc blende. These minerals occur as small 
irregular replacement bunches peppered through the quartzite bed. 
An open cut higher up the hill shows other similar quartzite beds 
also more or less mineraUzed. Tunnel B, on Slate Creek 200 yards 
north of the mouth of Prospect Creek, has been driven 50 feet into 
the same formation and the mineraUzed conditions here are practically 
identical with those above described. 

Sailor Boy. — ^The Sailor Boy prospect is located in the NW. i 
sec. 13, T. 46 N., R. 4 E. The mineral conditions here are practically 
the same as those ia the Silver Spray. The mineraUzed quartzite bed 
is about 2 feet thick and shows the same minerals in the same sparse 
proportions. A tunnel 75 feet long has been driven and a 30-foot 
crosscut and 20-foot shaft have been added to the main working. 

Mastodon. — ^The Mastodon or Rochester group of claims is in sec. 
8, T. 46 N., R. 4 E. Tunnel A of this group is driven about 75 feet 
into blue and Ught-gray slates and shales, which dip 8® N. It shows 
fine-grained quartzite beds containing a few smaU gash veins which 
are fiUed with siderite, pyrite, and some calcite, but no general vein 
or lode. Tunnel B, in the same formation, has been driven in 75 feet 
on the west side of the creek. Little irregular bunches of mineral 
occur here, sparingly disseminated through a bed of quartzite about 
2 feet thick, which is interbedded with the slates, as in the Silver Spray 
and Sailor Boy prospects. The minerals observed are pyrite, galena, 
siderite, calcite, and zinc blende. Tunnel C, driven some 200 feet 
into the same formation, shows a few very smaU stringer veins 
but no mineraUzation except a Uttle iron-stained quartz and some 
weathered siderite. Tunnel D, driven 150 feet into the same forma- 
tion, opens what ap{)ear8 to be a bedding thrust, the mineraUzation 
of which has partly replaced some of the sheared waU rock. The 
vein material is mostly siderite, now largely altered to iron oxide, 

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and some pyrite. Its maxiinum thickness is 4 feet, but in some 
places it thins down to less than a foot. 

Setser. — ^The Setser claim is located near the summit of Packsaddle 
Mountain, about 4 miles northeast of Avery. Development work 
consists of an adit and several open cuts. A shear zone is exposed, 
the planes of which bear irregular "knife-blade" seams of ore con- 
sisting of galena and sphalerite, with some chalcopyrite and pyrite. 
Fairly large pieces of "float" galena, said to have been found in the 
vicinity, indicate a possible occurrence of larger ore bodies. The 
shear zone trends apparently east and west. The country rock is 
bluish and greenish shale representing the upper part of the Newland 
("Wallace") formation. 

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Although many morainal deposits contam particles of gold, the 
metal is very rarely so abundant in them as to make their treatment 
profitable. This is, of course, due to the fact that running water has 
not had opportunity to concentrate the precious metals scoured by 
the glacier from the decomposed surface of the mountains. 

Geologic literature contains very little relating to such occurrences. 
According to Waldemar Lindgren,* a morainal deposit on the northern 
slope of Deep Canyon, just west of Duncan Peak, in eastern Placer 
County, Cal., has been worked on a small scale for many years. The 
locality is known as the Bob Brown claim. The rough gold, which 
is distributed throughout the deposit, evidently came from the 
vicinity of Duncan. Peak, which is rich in small gold-quartz veins. 
In Trinity County, Cal., MacDonald ^ noted sharp-cornered ''colors" 
occurring in glacial till, which was called "dead wash" by the earlj 
miners, because they found it practically barren. In the Juneau dis- 
trict, Alaska, Spencer ^ observed low-grade auriferous gravel in 
morainal deposits on Gold Creek, which, however, seem to be com- 
posed essentially of modified drift. 

Gold-bearing ground moraines were recently observed by the writer 
during hasty visits in connection with work in land classification 
at a number of places in mountainous portions of the Northwest, 
notably on the slopes of the Continental Divide about 50 miles 
west of Denver, Colo., and in the Cabinet Mountains in northwestern 
Montana. The deposits of greatest economic importance are located 
in Montana and are known as the Kennedy Creek and Libby Creek 
placers. The writer is indebted to Messrs. John A. Scott, Frank 
Thomas, Vaughan, Howard, and Brockman, proprietors and operators, 
for courtesies and information regarding these occurrences. 

1 Oral communicatios. 

I MacDonald, D. F., The Weaveryille-Trinity Center gold gravels. Trinity County, CaL: Bull. V. S. 
Oeol. Surrey No. 490, 1009, p. 60. 
* Spencer, A. C, The Juneau gold belt, Alaska: Bull. U. 8. Oeol. Survey No. 287, 1906, pp. M-9B. 


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The Kennedy Creek placer, owned by the Kennedy Creek Gold 
Mining Co. and comprising essentially the exploited part of the 
deposits here described, is located near Stark, in the Ninemile district, 
about 30 miles northwest of Missoula, Missoula County, Mont. The 
nearest railway station is Huson, a small place 14 miles to the south- 
east, on the Coeur d'Alene branch of the Northern Pacific Railway 
and the Chicago, Milwaukee & Puget Sound Railway, with which the 
property is connected by a good county wagon road of easy grade. 
Huson is also on Missoula River, which, uniting with Flathead River 
at Paradise, 30 miles to the northwest, forms Clark Fork of the 


The topography of the region is hilly to mountainous but for the 
most part not rugged. The property under discussion ranges in eleva- 
tion from about 3,300 feet in the open valley of Ninemile Creek on the 
southwest to 4,000 feet on the northeast, where it is backed by a 
steeply rising upland and a group of mountains culminating in Squaw 
Peak (also called Skiotah Peak) at 6,000 feet or more above the sea. 
The crest of the range here forms the line between Sanders and 
Missoula counties and the southwest boundary of the Flathead 
Indian Reservation. These mountains, as yet unnamed, seem in a 
general way to be the southeasterly extension of the Cabinet Moun- 
tains, with whose axis they are in alignment but with which they 
are not closely connected. They are separated from the Coeur 
d'Alene and Bitterroot mountains on the west by the valleys of 
Ninemile Creek and Missoula River. 

The drainage flows southwestward through Kennedy Creek, a small 
stream a few miles in length, into Ninemile Creek, a vigorous stream 
which flows southeastward and joins the Missoula at Ninemile, a few 
miles below Huson. For nearly a mile in the middle portion of its 
course the valley of Kennedy Creek is a V-shaped gulch a few hundred 
feet deep, forming a narrow necklike outlet for the upper portion. 
This upper portion widens into a crudely fan-shaped, nearly flat- 
bottomed basin about a mile in diameter. A low divide separates the 
basin from the drainage of Butler Creek, a similar but stronger tribu- 
tary of Ninemile Creek on the east, and a lower divide separates it 
from McCormick Creek on the west. The basin is openly timbered 
with stately pines and forms a pleasing natural forested park. With 
slightly rolling, benched, or terraced topography it inclines to the 
southwest, from an elevation of about 3,900 feet at the foot of the 
mountains and the Butler Creek divide to 3,600 feet at the outlet. 

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The deposits lie within the area which has been mapped by the 
United States Geological Survey as undifferentiated Belt series,* 
comprising a great thickness of tilted, folded, and faulted Algonkian 
rocks, chiefly sandstone and shale, and their slightly altered equiva- 
lents, quartzites and hard argillites. To judge from the materials 
composing the gravels, the country rock in the surroimding hills and 
mountains includes representatives of the formations well known in 
the Coeur d'Alene district as the Prichard, Burke, Revett, and St. 
Regis formations.' 

At the camp and the lower end of the gulch the creek crosses a zone 
of younger beds of soft sandstone and shale containing several beds 
of lignite, all dipping about 35° NE., toward the mountains. These 
beds are seemingly of Neocene age and are imconformable with the 
underlying Algonkian rocks. 

Covering the bedrock nearly throughout the region is a surface 
mantle of mingled clay and gravel. The general aspect of this mantle, 
with its flowing surface contours, low mounds, hummocks, shallow 
undrained sinks, and other topographic forms, well seen in the Nine- 
mile Creek valley, at once su^ests its origin as a ground moraine. 
It ranges from 8 to 20 feet in thickness, averaging about 15 feet. It 
is thumest where it has been eroded by Kennedy Creek and its tribu- 
taries. It is commonly known to the mining men who have exam- 
ined it as ancient lake gravel, but it seems plainly to be a subglacial 
or ice-laid deposit of till — a ground moraine. This is clearly shown by 
topographic criteria, as stated above, and also by the character of the 
material itself, the complete absence of stratification, the coarseness 
and subangularity of the gravel, the planed, polished, and striated 
surfaces of many of the pebbles, the typical bowlder-clay matrix, 
and the rock-flour silt impounded by the tailings dam below the outlet. 

The gravels, which form a lai^e part of the deposit, range up to a 
foot and a half in diameter. They are composed mainly of quartzite, 
sandstone, and softer argillaceous rocks, with some quartz, hematite, 
and barite, all apparently derived from the formations of the Belt 
series. The matrix is typical brownish and bluish bowlder clay, 
with usually a small percentage of arenaceous or gritty material. 
A remarkable feature of the deposit is its high degree of consolidation, 
necessitating vigorous effort with the miner's pick to loosen almost 
every individual pebble in it, however small. 

The material seems evidently to be derived from tlie upland and 
mountains on tlie northeast, whence as sedentary soil, oxidized rock 

1 Calkins, F. C, A geological recomialssanoe In northern Idaho and northveatem Montana: BnlL U. 8. 
Oeol. Survey No. 384, 1909, p. 28, PI. I. 

* Ransome, F. L., and Calkins, F. C, The geology and ore deposits of the Cosor d' Alene district, Idaho: 
TzoL Paper U. 8. Qeol. Survey No. 62, 1908, PL H. 

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dSbiis, and talus it was scoured off the surface by the ice sheet, 
shoved or dragged down the slopes, crushed, ground, and finally com- 
pressed beneath the ponderous ice mass into its present condition. 
The ice sheet probably covered the basin with a thickness of a 
thousand feet or more for a period of centuries. 


The gold is detrital. It is contained in the ground moraine or 
till that floors the basin and extends down the creek outlet to a point 
below the camp. This material is seemingly gold-bearing through- 
out. The gold is of avera^ coarse size, although no lai^e nuggets 
have yet been found. The pieces are usually flattened but rough 
and irregular in shape and many pieces have quartz adhering to or 
embedded in them, denoting that tixe metal is of comparatively local 
derivation. It is probably derived from quartz veins in the equiva- 
lent of the Frichard slate, the chief gold-bearing formation of the 
C<Bur d'Alene district,^ which seems to be developed in the adjoining 
mountains; but unfortimately the mountain region could not be 
examined during this work. The slate is probably also the chief 
source of the bowlder-clay matrix in the deposit. The gold has a 
good color and is reported to run about $19 a fine oimce. With the 
gold in the deposits is associated considerable fine black sand. 

The deposit on the whole, in view of its glacial origin, is remarkable 
for the large amount and the regular distribution of the gold it con- 
tains. A most unusual feature is the fact that this glacial deposit 
does not seem to have been concentrated by later streams, nor to have 
derived its gold from preexisting placers. If this view is correct there 
must occur in the mountains or uplands to the northeast, in the path 
of the ice that deposited the moraine, some rich gold-bearing veiQ or 
bedrock area as yet undiscovered. 

As during the period of glacial activity a considerable quantity of 
till similarly derived from the mountains was transported through 
the basia and apparently had to be raised 100 feet or more to cross the 
rim rock, it seejms possible that in this process of transportation some 
of the gold may have been left behind and helped to enrich the deposit 
which now floors the basin. 

The gold seems to be distributed areally throughout the deposit 
with remarkable uniformity. Vertically considered its concentration 
increases with increase in depth and is greatest on bedrock and ia 
the lower part of the gravel. 

Tests made of the deposit in six different shafts fairly well dis^ 
tributed over about half a square mile in the southerly part of the 
basin show the gold content of the deposits to range trom. 20 cents 

> Ransome, F. L., and CaUdns, F. C, op. oit., p. 14L 
94174'— BuU. 470—11 5 

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a cubic yard near tbe surface to about $5 a cubic yard in the bottom 
foot of gravel next to bedrock, from which it is readily apparent that 
the deposits contain considerable gold. By some mining men the 
amount of gold present has been estimated at $18,000,000. From 
the data obtained in the present tests, after reasonable allowance is 
made for bowlders, which in the lower part of the section constitute 
about 10 per cent of the material, the deposit in the southerly part 
of the basin seems to contain on the average about 80 cents a cubic 
yard, including everything from the surface down to bedrock, or 
about $4 a bedrock yard. This would amount to about $17,360 
an acre, or more than $5,500,000 for the Kennedy placer portion 
of the area examined. The estimate does not include the neck of 
the deposit in the downstream outlet, which in places attains a 
thickness of 80 feet or more and is known to carry considerable gold. 
In the basin as a whole, if gravel of this grade is present throughout, 
there is probably more than twice this value. 

Ample water for working the ground is available; it is supplied 
through a 5-mile ditch from Butler Creek on the east. Some of the 
gold has been mined by hydraulic methods, about a thousand dollars' 
worth having been taken out by the present company in the last few 
years, mainly from the lower part of the ground. Owing, however, 
to the extreme consohdation of the material and the stickiness of 
the bowlder-clay matrix, which adheres to the gravel and thus tends 
to carry the gold along with the gravel into the tailings, ordinary 
hydrauUc methods are not adapted to this deposit. It will require 
apparently a very powerful dredge or hydrauUc elevator, first, to 
loosen the gravel which was so firmly consoUdated by the heavy 
overlying ice mass, and, second, to agitate the material forcibly in 
order to free the gold from the sticlgr clay matrix. Any attempt 
to treat the deposit by methods adapted to ordinary water-laid 
gravel seems certain to prove a failure. The gentle slope, softness, 
and smoothness of the bedrock floor and the ample water supply are 
favorable conditions for dredging, but owing to the unusual character 
of the deposit the greatest care should be exercised in selecting a plant 
adapted to it. 

Some mining men hold that soaking of the banks of the material 
successively exposed to the dredge pond after operations are begun 
will go a long way toward solving the problem. The experience of 
the writer, however, in obtaining samples from shafts which had just 
been imwatered for the purpose seems to show that little if any 
benefit can be expected from this mode of procedure, for the deposit 
is normally moist if not saturated and is not hardened by drought or 
baking as in an arid country. Blasting will probably prove the best 
means of loosening the material from its bed, after which, apparently, 
crushing or coarse grinding under a strong current or head of water 

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will be required to free the gold from its bowlder-clay matrix. In 
such a process the arenaceous or gritty material, though present 
only in small amount in the matrix, promises to prove an important 
feature, without which the deposit could probably not be worked. 

Attention should also be directed to the ridges forming the low 
divides between Kennedy Creek and Butler Creek on the east and 
McCormick Creek on the west. In the western part of the basin, 
a short distance above the outlet, the McCormick ridge rises to a 
height of about 100 feet above the floor of the basin with a narrow, 
rounded, almost crested top in places and with side slopes of 30° 
to 40°. In the half mile or more of its extent the ridge has a serpen- 
tine course. Similar features also characterize the Butler Creek 

The form and topography of these ridges and the vicinity and the 
little that could be seen of their geology indicate pretty clearly that 
during the melting of the ice at the close of the glacial period, while 
the basins and valleys were yet occupied by the ice masses, the 
drainage from the moimtains in the rear found its way out to Nine- 
mile Creek through subglacial tunnels or open ice-walled canyon-Uke 
channels coinciding in course with the present divides. In these 
narrow ice-bound channels the streams rapidly built up their beds 
with deposits of gravel and finer glacial d6bris, in some places to a 
thickness of 100 feet or more. When later the glacial streams and 
ice vanished, the stream-bed material remained and formed the 
present ridges, whose side slopes are due to slumping down of the 
upper portions of the material as the confining ice walls melted away. 

These eskerUke ridges accordingly consist mainly of stream-laid 
materials which differ totally from the ground moraine of the basin 
and in which there has been much greater opportunity for concen- 
tration of the gold. The ridges should therefore be crosscut at 
favorable pomts, preferably toward the base of the mountain, where 
the gold is most likely to have been dropped by the currents. Owing 
to the general looseness of these deposits and the rapidity with which 
they were laid down their gold is likely t<o be concentrated almost 
entirely in their lower portion. 

Placer deposits reported to be similar to those of Kennedy Creek 
are also worked on a small scale on McCormick Creek, to the west, 
but were not visited in this work. 


Since the foregoing description of the Kennedy Creek placer was 
put in type data for the following sketch of the Ninemile district^ 
in the southeastern part of which the Kennedy Creek area is located, 
have been received through the kind efforts of Mr. Prank Thomas and 
pioneers of the district. 

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From Kennedy Creek the Ninemile district extends northwest- 
ward up the Ninemile Creek valley nearly to its head, a distance of 
16 miles. The valley has a general width of about 8 miles; the por- 
tion to the northeast of Ninemile Creek, on the side of the higher 
mountains, is a mile or two wider than that on the southwest. 

The description of the topography given for the Kennedy Creek 
region applies to the district as a whole, but in the upper part the 
area is more heavily timbered, logging and lumbering having long 
been the chief industry. The sides of the valley are scored by numer- 
ous small tributary creeks or gulches which join Ninemile Creek at 
about right angles. These tributaries are largest on the northeast, 
where they number 12 or 15, and average about 4 miles in length. 
The area generally is easy of access; the coimty wagon road extends 
up Ninemile Creek nearly to its head, to St. Louis Creek, the head of 
the placer workings several miles above the pioneer town of Martina, 
which has long been a center of operations and was the seat of the 
early placer workings. 

Tlie gold placers of the district, so far as shown by the present de- 
velopments, are contained in approximately a mid-valley belt about 
3 miles in width and 14 miles in length, extending from Kennedy 
Creek to a point several miles above Martina. In this belt the de- 
posits seem to floor the valley in the form of a sheet whose continuity 
is interrupted by bedrock outcrops and stream-eroded areas. The 
deposits are best manifested and developed on the tributary streams, 
all of which carry gold. In the lower part of the district the deposits 
occur chiefly on the northeast side of Ninemile Creek; in the upper 
part they axe found on the southwest side, and also continuously 
along the creek itself for a distance of about 6 miles. The deposits 
are said to be similar to those of Kennedy Creek and seem to be 
chiefly of glacial origin. 

The first placer mining in the district was done in 1874, Messrs. 
Dickson, Barrett, Wolfe, Keim, Dickinson, Kennett, and Murphy be- 
ing among the earUer locators. In the middle seventies these men 
and others mined Ninemile Creek and its tributary gulches for about 
a mile above the present site of Martina and for a somewhat greater 
distance below. That much gold was produced is indicated by the 
amount of ground worked, the cost of working it, its richness, and 
the fact that with only the crude methods of operation then in vogue, 
several considerable fortunes were made out of the diggings. 

The amoxmt of this early production, which by some is estimated 
at several miUion dollars, is not known. As there was no assay office 
at Helena in those days, the gold was mostly sent to New York, San 
Francisco, Philadelphia, and elsewhere, in shipments of whidh no 
records are available. 

As this was prior to the advent of the Northern Pacific Railway 
in Missoula, supplies had to be freighted by team and wagon to 


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Missoula and then packed on the backs of animals to Martina, a dis- 
tance of 150 miles or more. The wage of a common miner, who could 
handle only a few cubic yards of dirt per day, was $6. Ground that 
would not pay more than this amount per man per day was not con- 
sidered. The richness of the gravel is further indicated by the fact 
that most of the ground is patented. 

Since the early period of activity some of the many properties dis- 
tributed throughout the district have not been worked for lack of 
sufficient water; others are now working and have been producing 
continuously on a small scale for many years. Among the latter are 
those of Fobert & Jamison, on McCormick Creek; Henry Bros., on 
Dutch Creek; the Chinamen, on Beecher Creek, and the Kennedy 
placer, on Kennedy Creek. On Beecher Creek, near Martina, a party 
composed of several members holds a 90-year lease on a property which 
it has worked with success for the last 12 years. On Kennedy Creek 
a CaUfomia dredging company has just completed a thorough sam- 
pling of the groimd with good results and is installing a dredge which 
is expected to be in operation in a few months. 

A considerable area of good ground, too flat for successful sluicing, 
on a south side tributary opposite Soldier Creek, about 2 miles below 
Martina, is being negotiated for by Boston men with a view of put- 
ting in a dredge. 

On Marion Creek the Marion Creek Gold Mining Co.'s property is 
being worked by lessees, and on Petty Creek the Hensolt placer, with 
a sawmill now on the gioimd, will commence mining as soon as the 
timber can be cleared off. On Ninemile Creek itself the deposits 
were mined wherever there was fall enough for sluicing. 

The conditions encountered in the district — ^lack of sufficient fall and 
meagemess of water supply for successful sluicing on much of the 
groimd, the consolidated condition of the deposits, and the favorable 
consideration given the groimd by those interested in dredging — sug- 
gest that the dredge or possibly some powerful plant of the hydraidio- 
elevator type may furnish the best means for working the deposits. 

Data for making an adequate forecast of the future of the district 
are not at hand. However, in case the gravels of the district as a 
whole compare favorably with those of the Kennedy Creek placer 
above described, as they seem to, it may be stated that after deduct- 
ing more than half the volume of the gravel sheet for postglacial 
stream erosion and bedrock wastage, and making due allowance for 
the fact that most of the gravels hitherto worked were probably sec- 
ondary, as in the earlier workings on Kennedy Creek, in which con- 
centration of the gold had taken place by glacial and recent streams, 
by rough estimate the district probably contains about $100,000,000 
worth of gold. 

Much of this gold, to judge from the attention the district is re- 
ceiving, will probably be won in the near future. The Chicago, 


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Milwaukee &Puget Sound Railway Co. has made a preliminary survey 
for a branch line up Ninemile Creek into the Flathead country on 
the north and is investigating, with reported good results, the lignite 
coal on Kennedy Creek with reference to its efficiency for locomotive 
steam fuel. The building of this railroad through the district, by 
affording cheaper labor, supplies, and freight rates, will greatly 
advance the placer-mining industry. 



The libby Creek placers are located about 85 miles northwest of 
the Kennedy Creek placer above described, on the opposite or 
northeast side of the Cabinet Mountains, in the southern part of 
Lincoln County, formerly a part of Flathead County. They are 
about 12 miles east of the Idaho State line and about 20 miles south 
of Libby, the nearest station on the Great Northern Railway, whence 
they are reached by wagon road. 


The deposits are located on the headwaters of libby Creek, which, 
heading on the northeast slope of the high, rugged Cabinet Moun- 
tains, drains northward into Kootenai River or North Fork of the 
Colimibia at Libby. The broad gravel-floored valley of Libby Creek 
trends obliquely to or nearly parallel with the moimtains and has a 
width of about 12 miles. It lies in open country and is simk from 
100 to several himdred feet below the general land surface. It 
and its main tributary valleys, according to Calkins,^ are located 
on approximately parallel faults trending northwest. The valleys 
are separated by long, sloping ridges, which toward the moimtains 
merge into a narrow belt of low rounding foothills. The topography 
is not rough, the irregularities of the bedrock being smoothed out 
by a mantle of glacial debris or lake deposits, producing gentle 
slopes of smooth contour up to elevations of about 6,000 feet. In 
the foothills and lower parts of the moimtains the vallejrs are deeper 
but in few places V-shaped or canyon-like. 


The bedrock of this valley ' consists essentially of members of 
the tilted, folded, faulted, and eroded Belt series, as at the Kennedy 
Creek placer and in the Cceur d'Alene district, Idaho. A consider- 
able area of the gold-bearing Prichard slate forms the crest of the 
range at the head of the valley. 

1 CattJDS, F. C, A geological mponnalManoB in nortbem Idaho and Dorthwwteni Kwitma; Bolt U. 8. 
Oeol. Survey No. 8M, 1900, p. 77. 

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Orerspreading the eroded bedrock floor, especially in the upper 
part of the valley, and rising in the mountains to 6,000 feet, is a sheet 
of glacial drift which in the valleys and low places attains a known 
thickness of nearly 100 feet. This drift consists almost wholly of 
typical ground moraine and was deposited by the ice sheet that 
moved from the mountains down the valley. In places about 75 
per cent of the drift is made up of subangular glacial gravels whose 
pebbles range from mere grains up to bowlders 10 feet or more in 
diameter, all embedded in a typical bowldery clay matrix. 

The deposits Ue within the area of continental glaciation as out- 
lined by Chamberlin,^ and it is quite possible that they may be 
compUcated by movements of ice belonging to the continental ^eet*. 
So far as present observations extend, however, it does not seem 
necessary to refer the origin of the deposits, especially of their gold 
content, to continental glaciation. 


Placer gold is reported to have been discovered in this region as 
early as 1867, but owing to the hostihty of the Indians, by whom 
several prospectors were killed, little work was done on the deposits 
for some time. All the earlier-workings are said to have been in the 
recent stream-washed gravels in or immediately along the present 
stream beds, and for a long time they furnished the principal mineral 
production of the Libby Creek and Cabinet Mountain district. 
These gravels were evidently concentrated by stream action from 
the sheet of glacial drift or ground moraine, on which they still in 
large part Ue. 

For the last 20 years or more, however, the gold has been derived 
principally from the till itself, where it occxu^ as placer gold. It 
is being mined at several points, principally at the Libby Placer 
Co.'s mine and the Vaughan-Greenwell mine. The placer produc- 
tion of the district for the period from 1902 to 1909, almost the 
whole of which came from these two mines, is $52,178.* 

The workable deposits seem to be confined to the valleys and low 
places. Attempts to open groimd on the higher slopes aad benches 
have not yet been successful. A large area of the higher deposits 
examined by the writer in this work was found to contain from a 
cent to a maximum of 6 cents in gold to the cubic yard, which is 
obviously too low a grade to constitute workable ground. 

Within the deposits the gold is irregularly distributed, in some 
places sporadically throughout the body of the till from top to bottom 
and in others in irregular, crudely horizontal but not definitely 

1 duDDbailii, T. C, BoekRoriiigs of fbd gnat loe in^raaioiiK SeTeafh Ann. Beiit. U. 8. GeoL Survey, 
>Min«dIl€foi]ioetU.&,Toti]mMfttfl903 to IMQ, U. 8. OeoL Sor^ey* 

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stratified zones, beds, or streaks idiich may possibly contain slightly 
modified till. The oxidized zone, several feet in thickness at the 
surface, is usually barren. 

The gold is mostly coarse or in nugget form. In about 8 ounces 
of it shown to the writer by Mr, J. T. Yaughan, at Libby, the pieces 
ranged in size mostly from that of a pea to that of the end of a man's 
finger, with some $8 to $10 nuggets. Some pieces showed con- 
siderable quartz adhering to or embedded in them. Others showed 
considerable wear or rounding, apparently more than could have 
been effected by transportation in the till from the crest of the range 
to their present location, a fact which suggests that some of the gold 
may have been gathered by the glaciers from pregladal placers. 

The gold has a bright color; much of it is deep yellow; rarely it is 
coated reddish. It runs 0.926 to 0.945 fine as a rule,^ but some is 
reported to run as high as 0.970 fine. 


Of the two mines here described the older is the libby Placer CJo.'s 
mine, also locally known as the Howard mine. It is located on the 
Ooldhill-Montana-Kootenai claim group, about 20 miles south of 
libby, on Libby Creek, which here flows between steep bluffs 80 feet 
or more high, carved in the glacial drift. The mine is in the east or 
right bluff, in which the gold is distributed from base to top and for a 
known distance of an eighth of a mile or more parallel with the course 
of the stream. 

At the time of the writer's visit the mine was in quarantine and a 
close examination could not be made. From oral reports of the 
operators, and from the apparent continuity of the deposits with 
surrounding exposures that were examined, the deposit containing 
the gold, which is well exposed in the face of the bluff, seems to be 
typical ground moraine throughout, with a bowlder-clay matrix and 
subangular gravel and bowlders ranging up to 10 feet or more in 
diameter. To judge from a break in the continuity resembling an 
erosional imconformity above the middle of the section, two epochs 
or periods of deposition seem to be represented. 

The ground is worked by hydraulic methods under a powerful head 
of water, both groimd and box sluicing being employed. 


The mine owned and operated by Yaughan & Greenwell is located 
on the Eldorado claim group a short distance upstream from the 
libby placer mine, on Howard Creek, an important east tributary of 
libby Co^ek. It has been producing for about 20 yeais; in the 

1 ICbieni Besoones U. 8. for 1908, pt. 1, U. 8. GeoL Surrey, 1909, p. 460. 

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period from 1904 to 1908 it yielded about $5,000 a year in the hands 
of lessees. The rate of production is limited by the water supply of 
Howard Creek for sluicing, which requires a veiy strong head of water. 

The mine is opened and worked principally at two points about 
half a mile apart. The lower opening is on the east side of the creek, 
which here flows at an elevation of about 3,700 feet. From the creek 
the deposit rises gently eastward for about an eighth of a mile, to a 
height of about 150 feet; its extent parallel with the creek is some- 
what greater. It rests upon a streamward-sloping bench or roughly 
eroded surface of quartzite which dips gently to the east, away from 
the range. 

The deposit seems to be groimd moraine. It is nowhere much 
over 30 feet in thickness and probably averages about 15 feet. Two 
periods of deposition are apparently represented. The basal part of 
the section is consolidated and cemented somewhat like hardpan, aad 
its gravels are decidedly subangular. Blasting is employed to loosen 
it from its bed. 

The gold is distributed more or less irregularly throughout the 
deposit. It is obtained by ground sluicing, in which it collects in 
the rock joints and cavities that serve as riffles, box sluices being too 
fragile to withstand the impact of the coarse gravel. The topog- 
raphy suggests that the deposit was probably derived from the high 
mountains to the west of Libby Creek, aad if so its normal course of 
transportation by the ice was probably disturbed by the Howard 
Creek glacier at this point and by the rim-rock hiU, on whose stoss 
side therefore the deposit lies, the conditiouB beiug similar to those at 
the Kennedy Creek placer. 

At the odier opening, located about half a mile farther upstream, 
the deposit is reported to be about 100 feet in thickness and to 
consist likewise of till or bowlder clay in which the gold is irregularly 
distributed throughout. 

The source of the libby Creek gold is commonly thought to be a 
porphyry ''dike" or "ledge" which, to judge from a specimen shown 
to the writer by Mr. Brockman at Libby, is a coarse siliceous 
granitic aad pyritic rock allied to granite porphyiy. The-dike has 
a width of about 200 feet. It is said to extend across Howard Creek 
at a point about a mile above the Vaughan-Greenwell mine and across 
libby Creek at a point about a mile above Howard Creek; it is best 
exposed at the latter point. It is mostly covered, but not deeply, 
by glacial drift. No gold, it is said, has yet been found on the 
upstream side of the dike. The dike has not yet been prospected, and 
whether it is associated with quartz veins is not known. 

That this dike may be a contributory source of the gold mined 
seems probable. However, the heterogeneous character of the drift 

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and the wide distribution of the gold in it indicate that most of the 
gold has probably come from points much farther up in the mountains, 
probably in large part from the area of the Prichard slate that is 
bounded on the west by the great Snowshoe fault, along which and in 
neighboring parallel fissures occur gold-bearing quartz veins and the 
important mineral deposits of the Snowshoe and other mines.^ It is 
likewise probable that the drift-covered rocks here contain gold- 
bearing blanket veins or ore beds parallel with the stratification, 
similar to those on the head of Fisher Siver, 10 miles to the east, 
described by Calkins,^ and that these may be an important source of 
the gold. 


Probably much remains to be learned concerning the extent and 
nature of the deposits above described. That the gold occiu^ in what 
is essentially a ground moraine there seems to be no doubt; that all 
the gold, however, is in primary placers and none of it derived from 
preexisting placers is not so certain. 

More extended field work by a geologist with practical training in 
glacial deposits would result in much benefit to the placer industry 
in both the Ninemile Creek and the Libby Creek districts. As a 
result of such work the more important of the deposits, not only in 
the ground moraine but also in other forms of drift, could be located 
by topographic and geologic criteria, and positions of esker-like ridges . 
and other more or less buried and obscure channels of glacial streams, 
along whose courses maximimi opportunity for concentration of the 
gold occurred, might be pointed out. 

It seems probable also that glacial placers similar to those here 
described may yet be found in other auriferous districts in the glar- 
ciated mountainous portions of the Northwest. 

1 CaUdns, F. C, A geological leoonnalasance in northem Idaho and northwestom Montana: Bull. U, 8. 
Qeol. Survey No. 384, 1009, PI. I, pp. 64, 103. 
* Idem, p. 103. 

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By R. W. Stone. 


In the jsummer of 1910 the writer exaniined ten townships in the 
Elkhom Mountains included within the land limits of the Northern 
Pacific Railway to determine the mineral or nonmineral character of 
the odd-numbered sections. The area is a small part of the Fort 
Logan and Helena quadrangles mapped by the Northern Transcon- 
tinental Survey on a scale of 1:250,000, or 4 miles to the inch, A 
2-mile strip along the west side of the moimtains is shown in greater 
detail, 2 miles to the inch, on the Boulder topographic map of the 
United States Geological Survey. The area had not been subdivided, 
except two townships which were subdivided in the spring of 1910 
and plats of which were not available. In order, therefore, to estab- 
lish the locations of the mineral deposits found and to depict the 
character of the region, it was necessary to prepare a suitable topo- 
graphic map. Elkhom and Crow peaks, the positions of which are 
known, were used as a base. This base line was very short, being 
little over a mile in length, but nevertheless proved satisfactory. A 
system of triangulation was developed over the entire area and town- 
ship and section comers on range lines on the east and west sides of the 
area were located by this method . The positions of the townships hav- 
ing thus been established on a scale of 1 mile to the inch, the detailed 
mapping was done by transferring such portions of this triangulation 
as were needed to other sheets and making individual township 
plats on the scale of 1:31,680, or about 2 inches to the mile. The 
work was begun July 20 and, although hindered at times by smoke 
from distant forest fires, was carried on continuously and completed 
October 14, 1910. A topographic map of nine townships was drawn, 
T. 6 N., R. 2 W., being omitted. W. R. Hill, of Seattle, Wash., was 
topographer of the party, and Blaine McLeon, of Helena, Mont., 
acted as station recorder. The writer examined hundreds of mineral 
prospects and made a reconnaissance geologic map of the area. Work 
was begun near Elkhom and proceeded north to McClellan Creek, 
east to Winston, south to Radersburg, and thence west and north to 
Jefferson, thus completing a circuit covering the whole area. 


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Numerous section comers found in T. 8 N., Rs. 1 and 2 W., made it 
possible to locate accurately on the topographic map each section 
in those two townships. The east side of the area examined is the 
Montana principal meridian and a number of section comers found 
along it, together with comers on the first standard parallel norths 
which is the south boundary of T. 5 N., Rs. 1 and 2 W., and comers 
along the west side of R. 3 W., controlled the position of the land 
net in the other eight townships. The resulting map shows the 
location of mines and prospects in the correct quarters of the 40-acre 
tracts. Although many of the geologic boundaries are drawn accu- 
rately, others are only approximate, especially those of the granite 
intrusions, which were crossed by a traverse in one direction only 
and could not, for lack of time, be traced in detail. 


The area described in this paper includes T. 5 N., Rs. 1 and 2 W. ; 
T. 6 N., Rs. 1, 2, and 3 W.; T, 7 N., Rs. 1, 2, and 3 W.; and T. 8 N., 
Rs. 1 and 2 W. As shown on the accompanying map (PI, III), it 
is located southeast of Helena, in Broadwater and Jefferson coun- 
ties. II lies between Missouri River on the east and the Helena^ 
Butte branch of the Great Northern Railway on the west. It is in 
the Helena land district and includes the Elkhom National Forest. 
The region is mountainous, ranging in elevation from 4,600 feet at 
the Keating mine to 9,380 feet at the top of Elkhom Peak. There 
are two main moimtain masses, separated by the valleys of Prickly 
Pear and Crow creeks. The largest area of comparatively gentle 
topography is a shale flat in the southeastern part of T. 5 N., R. 2 W. 

The drainage, which is tributary to the ACssouri, flows mainly in 
the headwaters of Beaver, McClellan, Warm Spring, Prickly Pear, 
Muskrat, Elkhom, and Crow creeks. On account of the forest cover 
and the precipitation of both snow and rain throughout the simimer, 
all the streams are perennial. These streams have in places cut 
through the volcanic rocks and been superimposed on the underlying 
folded sedimentary rocks, with a result that sonie of them have cut 
straight across upturned quartzite and limestone. Johnny Gulch 
is an especiaUy good example, passing from a broad, open shale area 
through limestone canyons and out into shale again. 


The Elkhom Mountains have been producers of precious metals 
almost since the earliest settlement in this part of Montana. In 1858 
gold placers were worked extensively on the heads of Wilson and 
other creeks, and in the sixties numerous quartz locations were made 
throughout the mountains. The district attracted more attention 
when the Elkhom mine became a producer in 1870. This mine, on 
which work has progressed spasmodically to the present time, has 


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been one of the prominent silver mines of the country and in 1910 
was in active operation. Besides this well-known district there are 
also a number of other groups of mines of more or less value. The 
principal ones to be mentioned in this paper are those at Radersburg, 
where are located the. Keating and Black Friday mines, large pro- 
ducers at the present day; Hassel, formerly known as St. Louis, on 
Indian Creek, which is variously estimated to have produced from 
S2,000,000 to $8,000,000 in gold from lodes and placers; the Park 
mines, on the head of Indian Creek, where there are several miles of 
underground workings; the Custer and Iron Age mines, near Win- 
ston, which have produced several hundred thousand doUars in gold 
but are now idle because of litigation; the Stray Horse and East Pa- 
cific mines, on Weasel Creek, which are reported to have yielded 
several miUion dollars in gold and silver. Also among the former 
producers are the group on Maupin Creek, including the Pilot, 
Euclid, and Qolden Gate mines, on which a mill was operated for 
a number of years; and those in the district at the head of Warm 
Spring Creek, where are the Carbonate Chief, Bell, B. & G., and others 
that have produced considerable amounts of gold and silver but were 
standing idle in 1910. The above-mentioned mines include only 
those which have several hundred feet of imdei^ound workings and 
probably employed at one time a score or more of men each. 
Throughout the mountains in each of the townships there are numer- 
ous small pits or prospects representing the work of a few days or a 
number of months, many of them showing sufficient mineral values 
to be worthy of some exploitation. 

The only geologic work done in the area by the United States 
Geological Survey previous to -1910 consists of a reconnaissance by 
W. H. Weed in the western part of the area and a detailed examination 
and report on about 9^ square miles in the vicinity of Elkhom. 
Weed first visited the Elkhom district in the summer of 1896 while 
studying the general relations of the granite area in which the Butte 
ore deposits occur. In 1897 he spent a fortnight in the reconnaissance 
of the Elkhom district and determined on a detailed mapping and 
study of the geology and ore deposits near Elkhom. R. H. Chapman 
made a topographic map in the immediate vicinity of Elkhom in the 
sunomer of 1899, and Joseph Barrell mapped the distribution of the 
rocks. The underground work in the Elkhom district was done by 
Weed. The resulting report * was published in the Twenty-second 
Annual Report of the Survey. The only other geologic report which 
the writer has found covering any part of the area here described is a 
paper by D. C. Bard, M. E., of Butte, Mont.* 

1 The geology and ore deposits of the EUchom mining district, Jefferson County, Mont: Twenty-second 
Ann. Kept U. 8. QtoH. Survey, pt. 2, 1001, pp. 3efH»60. 

s Notes on the geology ol the lUdersburg district, Montana: Jour. Assoc Eng. Soc., voL 45, No. 1, July, 
mo, pp. 14-17. 

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This mountam group lies on the eastern edge of the great Boulder 
batholith or mass of granite which extends from Helena southward to 
a point 20 miles beyond Butte and from Elkhom west to Deer Lodge. 
This batholith is composed chiefly of granite but includes also con- 
siderable masses of apUte and granite porphyry. The mountains 
include an area of folded limestone, shale, and quartzite, which are 
Intruded and overlain by a great outpouring of volcanic rocks, mostly 
andesitic in character. These volcanic rocks consist very largely of 
porphyry, breccia, and tuff, but the different phases are so intimately 
intermingled and the time for doing the work was so short that it was 
not possible to differentiate them in mapping the geology. Both the 
folded sedimentary rocks and the volcanic rocks contain intrusions of 
granite. The sediments, which are exposed on north-south folds, 
range in age from Algonkian to Cretaceous. They retain their normal 
character in the southermost townships but are highly metamorphosed 
where they lie in contact with granitic intrusions. 


After the deposition of the Cretaceous shale, probably Benton, 
which is the youngest consoUdated sediment in the region, this area 
was subjected to strong dynamic forces which warped the strata into 
north-south folds. This folding took place certainly not earlier than 
middle Cretaceous nor later than Laramie time. Subsequent to the 
folding there was an intrusion of gabbro the main bodies of which are 
found near Elkhom. This gabbro is the oldest igneous rock in the 
mountains. No evidence is to be had as to the former extent of the 
mass, for it is cut off abruptly by the giranite. There is some evidence 
that the mass cooled under a great cover of sediments, now largely 
worn away. 

In early Tertiary time there was a period of great volcanic activity 
and large quantities of igneous rock were injected into the sediments 
and poured upon the surface. It is possible that some of this material 
was derived from vents several miles to the west, in the area now 
occupied by the Boulder batholith, but it is equally evident that some 
of it was of local origin. Elkhorn and Crow peaks and the McOellan 
Range, north of Crow Creek, are in the writer's opinion the source of 
a considerable part of the volcanic rocks which must have covered 
the whole region to a considerable depth. This opinion is based on 
the occurrence of considerable amounts of volcanic breccia on these 
peaks and along the top of the range, and also on the radiate drainage 
of the area. It will be seen by reference to the accompanying map 
(PL III) that the streams radiate rather markedly from Elkhom and 
Crow peaks as one center and from the McClellan Range as another. 
This suggests that they were originally developed on two domes. 

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Consequent streams on the lava flows on the flanks of a volcano would 
flow away in all directions, and it is fancied that these streams 
assumed their present courses on such lava flows, which were long ago 
worn away. Th^ surface on which the breccia and lava were poured 
out was a highland of more or less rugged character, possibly as rugged 
as the present mountains. 

Later in the Tertiary period came the intrusion of the great mass 
of granite already mentioned as the Boulder batholith. Patches of 
metamorphosed andesites resting on the granite at several points in 
the batholith and inclusions of andesite along the border of the mass 
are evidence of its later age. It is believed that the granite was 
intruded in the andesites and possibly at or near the contact with the 
underlying sediments. At least it is practically certain that the 
granite was under a cover of about 1,000 feet of volcanic rocks. The 
heat of the great granite intrusion metamorphosed the andesites and 
also the sediments with which it came into contact. Since the 
intrusion of the granite subaerial erosion has removed the thick 
volcanic cover from a great part of the bathoUth and cut into the 
granite to depths of 2,000 and 3,000 feet. After the removal of the 
cover from the granite, but possibly before it had been deeply in- 
trenched, there were several outbursts of rhyolitic magma, some of 
which remains in the Elkhom Mountains, as, for example, the rhy- 
elite cap of Lava Mountain at the head of Warm Spring Creek and 
small masses of obsidian and rhyolite observed at a number of other 
points in the west half of T. 8 N., R. 2 W. 

Since Miocene time there has been no further marked disturbance 
of the region. A few small faults have been observed ill the vicinity 
of Elkhom and more or less sheeting or distortion of the granite has 
taken place. Ordinary atmospheric agencies have carved the region 
to its present form. By this process, as already mentioned, at least 
a thousand feet of volcanic cover have been removed from the batho- 
lith and the granite has been deeply trenched. Local glaciation has 
had a marked effect on some of the topography, as shown especially 
by three superb cirques on the flanks of Elkhom and Crow peaks. 
Each of these cirques holds a small lake. There are a number of 
glacial moraines around the highest peaks, one of the most conspicu- 
ous being a morainal ridge just above the town of Elkhom which 
completely dams the valley. 

A general tilting which ponded the rivers of the State formed the 
great Tertiary lakes. Into the lake which occupied the valley of 
Missouri and Boulder rivers the streams from these moimtains carried 
their great quantities of waste and deposited them as stratified beds 
of clay and sand, now known as the Tertiary lake beds. A small 
area of these deposits at the Keating mine, on the east side of T. 5 N., 
R. 1 W., is shown on Plate III (p. 76). 

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Igneous rocks occupy about seven-tenths of the area shown on 
Plate III. To judge by the numerous granitic intrusions in the sedi- 
mentary rocks, it may be concluded that a body of granite lies not 
far below the surface of much of the remaining three-tenths of the 
area. The varying character and different origin of these rocks and 
their relation to the ore deposits make them the leading feature of 
the geology. 'Hie geologic map shows their occurrence so far as 
known at present. 

Rocks of andesitic type are most abundant, occupying an area 
equivalent to about five townships. They embrace a wide variety 
of both intrusive and extrusive origin and include porphyry, breccia, 
and tuff. Ttey vary from light gray to dark in color and from rocks 
devoid of phenocrysts to distinctly porphyritic forms, the latter being 
commonest. Breccia is common on Elkhom Peak and along the 
McClellan Range but so far as observed is nowhere very coarse, 
included angular fragments rarely measuring more than a few inches 
across. Tuffs found in the same localities are the finer fragmental 
ejectamenta from volcanic eruptions and in some places show pro- 
nounced bedding or stratification. Examination with a hand lens 
shows that the white grains making conspicuous bands or flow lines 
are crystals and angular fragments of feldspar. 

Granite occupies an area equivalent to two townships and is found 
everywhere in the valleys of Thoroughfare, Muskrat, Prickly Pear, 
and Warm Spring creeks and on the west of McClellan Creek. In 
this region it is rather basic in character, halfway between granite 
and diorite and therefore, strictly, a monzonite. It is readily recog- 
nized as the. coarse granular rock occurring all along the west side of 
the mountains. This rock varies somewhat in appearance, depend- 
ing on the size of the grains and on the abundance of the ferromag- 
nesian minerals. A later intrusion into the granite mass from a more 
acidic magma, called aplite, is distinguished by lighter color and 
finer grain. This phase is common on the west flank of Elkhom 
Peak and along the border of the batholith, especially in the valley 
of McClellan Creek, but the purely reconnaissance character of the 
geologic mapping did not permit its differentiation. Another phase of 
the same granite magma found at a number of places is a rather red- 
dish coarse-grained granite porphyry, containing large pink ortho- 
clase phenocrysts. It was observed in the trail gap just west of the 
head of Tumley Creek; near the Olga mine, at the head of Whitehorse 
Creek; and near the Pilot mine, on Maupin Creek. 

Gabbro and diorite are the oldest igneous intrusions in the moim- 
tains and occur only in very small patches. The lai^est area of gab- 
bro is around Black Butte near Elkhom and is about half a mile across. 
Two smaller areas lie 1,000 feet north and east. The main outcrop 

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of diorite is on the ridge east of Elkhom, just north of the upper rail- 
road bridge in Queen Gulch. It is a little more than half a mile 
across and is completely surrounded by limestone. There are basic 
granular igneous rocks on Wilson and Eagle creeks^ forks of Crow 
Creek, but neither their extent nor their exact character was deter- 

Bhyolite is the youngest igneous rock found in the mountains. It 
is light gray, has felsitic texture and flow structure, and occurs 
principally as the cap of Lava Mountain and of several smaller buttes 
just west of the west boundary of T. 8 N., R. 2 W. Besides these 
large bodies there are several small ones a few rods in extent. Black 
obsidian occurs at a number of points, as near the Carbonate Chief 
mine and at Fritz Invay's prospects, which lie between the Good 
Cheer mine and the Willard claims. 


Consolidated sedimentary rocks occupy about three-tenths of 
the area. The units shown on the geologic map (PL III) are litho- 
logic but also in part represent formations. They can be readily 
distinguished both by the rock composition and by the topographic 

Algofikian shale. — ^In the southeastern part of T. 5 N., R. 2 W., 
there is an area of 6 or 7 square miles underlain by red shale including 
some green shale and thin beds of sandstone. This corresponds to 
the red shale at Townsend and is the oldest rock in the region. It is 
believed to represent the Spokane shale of areas to the east. It 
makes a sage-covered flat of very gentle relief compared with the rough 
quartzite and limestone ridges on the east and west. 

This shale, metamorphosed to homstone by proximity to igneous 
intrusions, is seen on the ridge southwest of Elkhom in a long, narrow 
outcrop and has been called by Weed the Tumley homstone. The 
thickness of the formation is not known, for the base is nowhere 

Oawbrian quartzUe. — Overlying the red shale is a formation of 
white to pink quartzite about 125 feet thick. It is correlated with 
the Flathead quartzite, the base of the Cambrian in central and south- 
em Montana. Its outcrop is confined to short interrupted sections 
near Elkhom, to a circular outcrop near the Silver Bell mine on 
Johnny Gulch, and to a conspicuous loop along the boundary be- 
tween T. 6 N., R. 1 W., and T. 5 N., R. 2 W. Here, because of its 
superior hardness and tilted position, its dip ranging from 30^ to 70^| 
it forms a sharp ridge or wall. 

Ckmbrian to (hrbaniferoua limesUmes. — ^Above the quartzite just 
mentioned is a series of formations composed very largely of lime- 
stone and approximately 4,000 feet thick, which in this paper are con- 

94174*— Bull 470—11 6 

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eidered as a unit. The base is a shaly series possibly corresponding 
to the Wolsey shale. It is well exposed in sees. 19 and 20, T. 5 N., 
R. 1 W. Above this are Cambrian limestone formations named and 
described by Weed in the report on the Elkhom mining district, a 
shale possibly of Devonian age, and at the top the Madison limestone 
(Lower Carboniferous, Mississippian), 1,500 to 2,000 feet thick. The 
Madison is massive, is light colored to white, stands at a high angle, 
and makes conspicuous cliffs and ledges. It outcrops prominently 
in the five townships of the southern half of the area. 

Quadrant formation. — ^The Quadrant formation (upper Carbonifer- 
ous, Pennsylvanian), which in this region is mostly quartzite and 
about 380 feet thick, immediately overHes the Madison limestone. 
Like the upper part of the Madison it is very light colored, and where 
it is tilted to a high angle, as along its north-south course in Tps. 5 and 
6 N., R. 1 W., it forms a hogback ridge and can be traced very readily. 
It is metamorphosed to homfels north of Elkhom, where it is in con- 
tact with granite and aplite. It is possible that the formation as 
mapped in the east half of the area may include more than the Quad- 
rant. The writer surmises that further study might show the pres- 
ence of the Sundance formation (Jurassic) or its equivalent on the 
heads of Slim Sam Creek and Keating Gulch, for an outer and lower 
ridge of a sandy nature is closely overlain by shale having the strati- 
graphic position and general appearance of the Morrison formation 
(Jurassic or Lower Cretaceous). 

Jurassic to Oretaeeous beds, — ^The sedimentary rocks lying between 
the Quadrant formation and the andeeites were all included by Weed 
in his Crow Ridge series, because they are so highly altered around 
Elkhom that the different formations composing the series could not 
be distinguished. East of Queen Gulch, at a distance of several miles 
from the Boulder batholith, the rocks are unaltered, and further 
study probably would separate this unit into two or three formations. 
The writer is confident of the presence of the Morrison formation 
extending north and south through the middle of T. 6 N., R. 1 W., 
and thinks that the youngest beds, dark shales widely exposed in the 
basin of Slim Sam Creek, are Benton. The thickness of this unit 
has not been measured anywhere exeept near Elkhom, where it is 
1,680 feet, according to Weed. 

Tertiary laJce beds. — ^The lake beds of Tertiary age, consisting of 
clays and sands of very light color and possibly including some 
volcanic ash, are seen just south of the Keating mine and east of the 
Black Friday mine. The southeast comer of T. 6 N., E. 1 W., also 
is on these beds. They are the edge of a wide deposit which filled 
the valley of the Missouri when the drainage was ponded by warping 
of the crust. 

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The geologic structure of the mountains is shown by the cross 
section at the bottom of Plate III (p. 76). This section represents 
the relations of the rocks along an east-west line through Elkhom, 
and shows that the sedimentary rocks are folded in an elongated 
double curvei with a synclinal axis on Sand Creek and an anticlinal 
axis close to the line between Rs. 1 and 2 W. There are minor folds 
just west of Sand Creek and a prominent structural dome on Johnny 
Gulch at Parker's. The andesites lie comparatively flat in the central 
part of the area but dip to the east along the principal meridian. 
The relations below the surface shown on the cross section are neces- 
sarily more or less hypothetical. 


The ore deposits in the vicinity of Elkhom, as described in Weed's 
report, are closely related to intrusions of gabbro, diorite, and granite. 
A study of the map, which shows the location of mines and prospects, 
makes clear the fact that at a number of places in the mountains the 
ore deposits are closely related to intrusions of granite or granitic 
rock. Fissure veins occur in the granite some distance from any 
known contact and also in the volcanic rocks, where, on the surface 
at least, there is no evident relation to other types of rock. An 
intrusion of granite porphyry and aphte in granite is the locus of 
mineralization on Maupin Creek, and a body of diorite (?) in Eagle 
Gkdch 4 miles northwest of Hassel is the center of a small mineraUzed 
tract. There are some small accumulations of ores in limestone and 
quartzite which appear to be related to green porphyry sills, while 
others, apparently replacement deposits in limestone, so far as dis- 
covered have no relation to any intrusive rock showing at the surface 
but may be due to a mass of igneous rock lying close below the surface 
and not exposed near the deposits. 


Ab only a part of the area here described has ever been surveyed 
and marked out by townships and sections, the simplest method of 
description is by drainage basins. In part these coincide with mining 
districts. The discussion will therefore begin with the northernmost 
streams and proceed southward. 

The piuT)ose of the field work, as already mentioned, was to deter- 
mine the mineral or nonmineral character of the land in the Northern 
Pacific Railway land-grant limits. The question raised in this 
classification "is not whether the evidence, construed as in an 
ordinary contest between an agricultural and a mineral claimant, 

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shoifTB as a present fact that the land is more valuable for mineral 
than for agricultural purposes, or vice versa, but whether the evidence 
ehowB that it is reasonably probable that the land in controversy 
contains valuable mineral deposits." (30 Land Dec., 447.) Hun- 
dreds of mines and prospects were visited and evidence taken, but 
many shafts were partly filled with d6bris or water, tunnels were 
caved, padlocked, or otherwise inaccessible, and prospects had been so 
long abandoned that information could be had only from the dump. 
Under these conditions when a fair showing of ore was found the fact 
was noted and the kind of ore specified, but little or no information 
was obtained as to the character, size, or position of the ore body. 
It is therefore impossible for the writer to give more than a brief 
description of the distribution, relation, and character of the ore 


The Beaver Creek mining district is situated southwest of Winston, 
on the Northern Pacific Railway, and in 1907 ranked third in ton- 
nage from Broadwater County. In 1908 the output of this district 
was produced by five deep mines and one placer and consisted of 
$26,134 in gold, 19,314 ounces of silver, 7,056 poimds of copper, and 
180,191 pounds of lead.* The mines nearest to Winston are the Iron 
Age and Custer, which are on vertical pyrite-bearing quartz veins in 
andesite and andesite porphyry. In some of the ore shipped from 
these mines the gold has equaled the silver in quantity, and the copper 
has amounted to 3 pounds to each ounce of gold and silver. The 
Custer mine has a vertical shaft 600 feet deep and another 300 feet 
deep. The total length of its underground workings is nearly 4 
miles. The Iron Age mine also has a deep shaft and extensive levels. 
Both were idle in 1910 on account of litigation. There are a number 
of smaller mines in the immediate vicinity. 

In sec. 4, T. 8 N., R. 1 W., considerable development work has been 
done on east-west quartz veins in granite, but little ore has been 
shipped. At the Dolly Boy there is a shaft and two slopes on a 3-foot 
vein of quartz carrying sulphides, which looks like a fair grade of ore. 
This mine is adjacent to a group of claims including the Gold Hill, 
Bell Abraham, Homestead, Washington, Green Mountain, Silver 
Smith, and Neptun, which are said to aggregate about 1,000 feet of 
underground tunnels and to be on a quartz vein 1 J feet wide, carry- 
ing 8 per cent of copper and $10 in gold and 37 ounces of silver to 
the ton. This statement was made by the owner, George UflFel. All 
these claims are in a granite intrusion in the andesites. 

The East Pacific mine, on Weasel Creek, has a vertical shaft 1,000 
feet deep and four tunnels, the longest of which extends for 3,700 feet. 

iMIiwral BflSooioeBU. 8.for 1906,pt 1, U. S. QeoL Survey, 1909, p. 447. 

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This mine is said to have 2 miles of undei^ound workings and to have 
produced at least $2,000,000. It is equipped with a 75-ton mill using 
concentration and amalgamation and has shipped ore containing lead, 
silver, gold, and copper. The mine is in dark, finely porphyritic 
andesite, locally called ''diorite" and ''blue lime." The ore is in an 
east-west vein ranging from 3 inches to several feet in width and 
standing nearly vertical, with siliceous gangue. Galena and zinc 
blende with chalcopyrite and iron pyrite are the associated minerals. 
The ground was located in 1867 and patented in 1889; mining opera- 
tions ceased a few years ago. More recently lessees have been sorting 
the dumps and getting concentrates by jigging which are reported 
to average $45 a ton after deducting $6 or $7 smelter charges. These 
concentrates run $4 to $5 in gold and the rest in silver and lead. 
Five men were working here in September, 1910. 

One mile west of the East Pacific mine there is a granite intrusion 
in the volcanic rocks which has caused some mineralization and is 
the site of several smaU claims, including the Monte Cristo, St. John, 
Denver, and others. Most of the tunnels and shafts have been long 
abandoned and are caved. The lode in some places seems to be a 
cream-colored lava from which numerous cubical pyrite crystals have 
been dissolved out. On one dump siUceous gangue carrying small 
quartz stringers and pyrite was found. 

The January and Sunrise mines, on Weasel Creek half a mile south 
of the East Pacific mine, have yielded several thousand dollars each. 
The ore of the January mine carries galena and pyrite and is said to 
have produced $35,000. At the Sunrise mine free-milling gold ore 
was crushed in a 6-stamp mill. The tunnel is caved but seems to be 
in andesite near a granite intrusion. The ore is auriferous pyrite 
in quartz. 

The Stray Horse mine, at the head of Weasel Creek, consists of five 
tunnels and at least one deep shaft, the underground workings abro- 
gating several thousand feet. The ore is galena and pyrite carrying 
gold, sHver, and copper, and the mine, which has not been operated 
for several years, is said to have produced $200,000. It is on ver- 
tical east-west veins in andesite porphyry. 

About a mile south of the Stray Horse mine, on the mountain 
between Beaver and Whitehorse creeks, is a group of mines in a 
granite intrusion, including the Irish Syndicate (Big and Little 
Casino), Cynosure, Quartet, Emil H., Little Olga, and Champion. 
These are on north-south and east-west quartz veins, of which the 
former carry gold and the latter silver. Two of the properties were 
being worked in 1910 by three or four men each. 

The Irish Syndicate is on an east-west lode in porphyritic granite. 
It is said that $6,000 was taken in sinking the first 40 feet. Although 
the mine is not more than 150 feet deep, it has about 700 feet of under- 
ground workings and is said to have yielded $45,000, mostly in silver. 


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The Cynosure mine has a 180-foot tunnel and an 80-foot raise to the 
surface and was bding worked in 1910. Ore from this mine is pyritif- 
erous quartz said to carry gold and a little copper and lead, netting 9S5 
a ton. 

The Emil H. is on the same lode as the Little Olga, on an adjoining 
claim. It has about 800 feet of workings and yidded about $20,000, 
mostly in gold, according to verbal report. 

The Little Olga shaft is 125 feet deep and the vein was followed for 
100 feet. The ore is largely ai^ntiferous galena and yielded 5 pounds 
of lead to each ounce of silver. The ore assayed about 0.7 per cent of 
copper and $2 a ton in gold. The mine produced about $25,000 in 
gold and silver. 

The Champion mines are on a quartz vein carrying limonite, 
pyrite, and a little malachite and galena. The values are principally 
in gold. After several hundred feet of shafts and tunnels had been 
opened the work was abandoned, and the property has been idle for 
several years. 


On the north branch of Jackson Creek, half a mile above the forks, 
in the northern part of sec. 11, T. 8 N., R. 2 W., there is a tunnel in 
very light colored fine-grained granite close to the contact with andes- 
ite. The ore on the dump seems to be mineralized country rock 
with small bunches of quartz carrying chalcopyrite, pyrite, and molyb- 
denite. Some of the coarser granite is highly pyritized. Molybdenite, 
of which only a few square inches was seen, occurs as a thin incrusta- 
tion on a joint plane. 

On tiie ridge south of Crystal Creek, in sees. 3 and 4, T. 8 N., R. 2 W., 
there are several prospects on quartz veins carrying pyrite. One of 
these, the Christmas Gift, is on a N. 60^ E. vein dipping 50^ S., which 
has be^i developed by ^ee slopes and two pits. The ore is pyrite, 
arsenopyrite, and chalcopyrite. An assay made by the United States 
assay ofi&ee at Helena, Mont., shows 0.10 ounce of gold and 1.2 ounces 
of silver to the ton. A 130-foot tunnel on the property of Mr. Weston 
in the bank of Crystal Creek is on a vertical quartz vein, in places 2 to 
3 feet wide, which is said to assay from $2.50 to $27 in gold to the ton. 
The ore mineral is mostly iron pyrite. In the immediate vicinity 
there are several other claims on similar ore, including the Lone Tree, 
which has a 50-foot shaft. 

In the northwest quarter of T. 8 N., R. 2 W., mostly in sees. 8 and 
17, there is an irr^ular area of granite porphyry, apUte, and some 
rhyolite surrounded by granite. In this area there are many pros- 
pects and a few small mines, located on quartz lodes trending nearly 
east and west and standing vertical. The principal lode has been 
developed for over a mile and on it are located the Pilot, Euclid, and 
Gblden Gate mines. The ore mineral is mostly iron pyrite, and the 

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principal value is in gold. The Pilot mine is said to have a 330-foot 
shaft and a 1^200-foot tunnel. At the Euclid mine th^e are nine 
shafts and a croescut. The main shaft is 200 feet deep. It is said 
iiiBt- some shipments from this mine carried over $80 a t<m in geld. 
The vein is on or near the contact between normal granite and a gran- 
ite porphyry intrusion. This mine has been shut down unee 1894. 

"Hie Golden Gate mine, located in 1884, is r^>orted by the owik&t, 
Joseph Gameau, to have a shaft 200 feet deep and 500 feet of levels 
on a quartz vein 70 feet wide bearing N. 88^ W. and pitching south 
at a very high angle. A 30-ton null and concentrator operated 
here were burned several years ago, and the mine is now full of water. 
Mr. Gameau says that the mine produced about $81,000 gross, mostly 
in gold, and that the bulk of the ore averages about $23 a ton. 

The Good Cheer mine, at the head of Maupin Creek, in the SE. i sec. 
17, T. 8 N., R. 2 W., has a shaft 165 feet deep and 400 feet of levels. 
It is on a 4i-foot vertical east-west quarts vein on or near the contact 
between grauite and granite porphyry or acidic granite. The quartz 
carries p3^te, chalcopyrite, and gi^ena. In 1910 Mr. Gameau, the 
owner, was shipping a little first-class sorted ore carryii^ over $15 a 
ton and said that up to that time the mine, which is still in the devel* 
opmMit stage, had produced about $8,000. 

The Black Bear claim, on the hilltop, a quarter of a mile southeast 
of the Good Cheer mine, is on an east-west quartz vein in granite 
and is reported by Mr. Gameau to carry 12 ounces in silver and $1.70 
in gold to the ton. Short black crystals of tourmaline were found 
in the ore on the dump. 

The Skookum lode, neax the Euclid mine, has an 18-foot shaft on a 
quartz vein between a granite hangiog wall and granite p<H^hyry 
footwall. Hie vein is 20 inches wide and has an 8-inch stringer 
carrying galena, chalcopyrite, azurite, and malacite. No ore has 
been shipped, but it is said to carry gold, sUver, lead, and copper. 

In the hiU back of a cabia on the bank of McClellan Creek in the 
southern part of sec. 16, T. 8 N., B. 2 W., is the Ironside claim. It 
is on a 3-foot v^ of quartz strildng N. 87^ W. and dipping 85^ N. 
The drusy quartz gangue carries iron pyrite and limonite, and an 
assay of selected specimens made by the United States assay office 
at Helena, Mont., shows 0.30 ounce of gold and 6 ounces of silver to 
the ton. 


The mines in the Warm Spring Creek district are mainly at the 
head of the middle fork, and are easily reached from Alhambra, on 
the Great Northern Railway. They are in an area of granite just 
south of the nuns of rhyolite and obsidian cm Lava Mountain. The 
mines are all on vertical east-west quartz veins carrying gal^ia, 
chalcopyrite, arsenopyrite, and iron pyrite. The Carbonate Chief 


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mine is opened by three tunnels, the longest about 1,700 feet. The 
Bell mine has three tunnels 500, 1,000, and 1,200 feet long. These 
two mines are reported by R. A. Bell to have jdelded $800,000 net 
(smelter returns) in gold, silver, and lead. Near them is the Mock- 
ing Bird, which has a vertical shaft 250 feet deep. These three 
mines were operated extensively in 1907 but have been idle since 
then. They produced in that year 41,829 tons of ore, which had a 
gross value of $952,327, mainly in gold and silver, though copper 
and lead were recovered. In 1906 the yield was 1,237 tons, with a 
value of $47,756. 

Half a mile west of these mines is the Eagles Nest group, consist- 
ing of 27 claims, including the B. & Q., Bland, Eagles Nest, and others. 
The B. & G. mine has an incline shaft 250 feet deep and three levels, 
aggregating about 1,200 feet of underground workings. The ore 
consists of pyrite, chalcopyrite, and galena and has assayed as high 
as $40 a ton in gold, silver, lead, copper, and molybdenite. Ore 
carrying 22 per cent of copper was found in the bottom of the shaft. 

About 800 feet east of the B. & 6. is the Eagles Nest mine, which 
has a shaft at least 100 feet deep, sunk in the winter of 1909-10 and 
showing the same ore as the B. & G. A 5-ton shipment is reported 
to have netted over $40 a ton. The Mocking Bird mine, below the 
Eagles Nest, is on similar ore and ia reported to have produced 
$10,000 to $12,000. 

The Willard group of claims, in sec. 20, T. 8 N., R. 2 W., at the 
head of the north fork of Warm Spring Creek, consists of the Dover, 
Relief, Osage, Alpha, and Union. They are located on two east- 
west nearly vertical quartz veins said to be from 8 to 20 feet wide* 
The Union shaft is reported to be 270 feet deep, with short crosscuts, 
but is now full of water. The Relief shaft is 60 feet deep and the 
Dover shaft is down 73 feet. Over 300 tons taken above water 
level in the Relief shaft is said to have netted over $40 a ton, and a 
carload of ore from a pit on the east end of the claim netted $55 — 
2 ounces of gold and the rest silver and lead. From a short tunnel 
below the discovery shaft on the Relief claim was shipped over 100 
tons that yielded $40 a ton net. Small shipments of ore have been 
made at infrequent intervals since 1889. The property was idle in 
1910. A sample of oxidized ore from a shallow pit assayed at the 
United States assay office at Helena showed 0.40 ounce of gold and 
16.2 ounces of silver to the ton. 

Fritz Invay's claims, in the southwest comer of sec. 17, T. 8 N., 
R. 2 W., on the head of Maupin Creek, are developed by small tun- 
nels and shafts, the deepest shaft being 60 feet deep. In this shaft 
a body of green obsidian was encountered. The quartz vein, which 
is about 1 foot wide, carries impure sfdialerite, galena, chalcopyrite, 
pyrite, and siderite. 

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The Prickly Pear Creek district is adjacent to the Corbin district and 
is entirely in granite. Only at two or three localities in it have ore 
deposits of any moment been found. One of these is at the mouth 
of Golconda Gulch, in sec. 17, T. 7 N., R. 3 W., where the Big Chief 
mine has opened up several hundred feet of tunnels on a quartz 
vein carrying pyrite and galena ore. To judge from the appearance 
of the property, which has been idle for several years, probably a 
considerable quantity of ore was shipped from this mine reputed to 
carry values mostly in gold and silver. Farther up the gulch there 
are a number of prospects on small quartz veins probably carrying 
some gold, and on the mountain side in sec. 28 a quartz lode carrying 
free gold has been recently discovered in the Golconda group of claims. 
Rusty quartz from the property carried 0.40 ounce of gold and 2.6 
ounces of silver to the ton, according to the United States assay office 
at Helena. Development work was progressing on this property in 
1910 by driving a short tunnel to undercut the vein. 

Grolconda Gulch and Prickly Pear Creek have been washed for 
gold-placer ground at a number of places. 


The Perk mines are located in sec. 15, T. 7 N., R. 1 W., about 6 
miles northwest of Hassel, on Indian Creek. The claims are mostly 
on quartz veins in andesite and the development amounts to several 
thousand feet of underground workings. The ore of the Park mines 
is mostly pyrite, with some arsenopyrite and galena, and the principal 
value obtained is in gold. The entire group of mines was idle in 1910 
and apparently had not been operated for several years. A mill and 
cyanide plant were once built here to handle the ores, but the recovery 
of precious metals by the processes used was not successful. 

Half a mile east of the Park is the Little Anna mine, which has a 
slope driven northwest at an angle of 35*^. The ore is quartz carry- 
ing arsenopyrite and pyrite. The size of the dump indicates that 
there are several hundred feet of underground workings. The mine 
has been idle and full of water since 1904. The Iron Mask mine, in 
sec. 24, has a vertical shaft probably over 200 feet deep on a quartz 
ledge in coarse andesite porphyry. The ore is mostly oxidized iron 
and galena. This mine yields silver and lead but was idle in 1910. 

The Silver Wave mine, in sec. 26, is working on a lode that trends 
N. 60*^ W. and dips 80® N. The country rock is fine-grained black 
andesite and the ore is mainly pyrite and galena. It is said to net $35 
a ton, the main value being in gold, with some silver and lead. The 
shaft is 350 feet deep, and 24 men were engaged here in September, 
1910. Just north of this mine is the New Year group of claims, on 

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Similar ore deposits, and a nule to the west is the Crosscut mine, con- 
sisting of two shafts more than 50 feet deep and one shaft probably 
250 feet deep on a vertical vein in green and black fine-grained andes- 
ite. The ore seen on the dump is quartz carrying pyrite, with values 
probably mostly in gold. There are numerous other small prospects 
in this vicinity, many of them showing small amounts of ore. 

In 1908 nine quartz properties in the Park district and at Hassel 
yielded $5,313 in gold, 2,939 ounces of silver, 8,901 poimds of copper, 
and 27,374 pounds of lead.* 

Hassel is located 6 miles west of Townsend, on the Northern Pacific 
Railway, on Indian Creek in the northeast comer of T. 6 N., R. 1 W., 
in an area mainly of andesite porphyry. There are, however, in this 
vicinity at least two intrusions of granite which probably were the 
cause of extensive mineralization. This district first began to pro- 
duce about 1860, when the creek was discovered to be good placer 
ground. The working of this placer led to the discovery of veins in 
the inmiediate vicinity carrying good values in gold and of irregular 
masses of mineraUzed porphyry in Diamond Hill. Open-pit mining 
and long tunnels in these large bodies produced approximately 
$500,000 in gold. One tunnel 2,800 feet long is said to be all in ore 
assaying from 80 cents to $2.50 a ton. Three small stamp mills were 
built and it is reported that one of them used to yield $500 a day when 
water could be obtained. The Little Giant mine, originally developed 
on east-west lodes dipping about 80^ S. in country rock consisting 
mostly of andesite breccia, was an extensive operation. A single 
vein seems to have been developed by open cuts and two tunnels. It 
is reported that the lower tunnel was driven for 1,500 feet on the vein 
and stoped ore the whole distance, and the upper tunnel, 1,000 feet 
long, was also aU in ore. As seen now in the open cuts the ore body 
appears to be mineraUzed country rock along a fracture. The vein 
has smooth walls and ranges from a few inches to several feet in width. 
The dumps show various deeply iron-stained andesite porphyries 
and breccias. Almost no quartz is found, the gangue being a cream- 
colored soft rock carrying red oxidized iron. It is generally reported 
that the Little Giant mine produced nearly $300,000, for the present 
company has smelter returns of about $200,000. Some believe that 
40 per cent of the values were lost in the tailings and that thousands 
of tons of ore on the dumps carry good values in gold. In 1910 the 
Little Giant Mining Co. was driving a tunnel to undercut the lode 
which was formerly worked by two long tunnels on the vein. This 
new tunnel in September, 1910, was about 500 feet long. 

The Blacksmith mine, at Hassel, has a deep vertical shaft on a 
body of ore said to be 30 feet wide, assaying about $10 a ton. Large 
quantities of ore from this mine have been milled, but some metal- 

1 litaienl RflMOioa U. 8. for 1906, pt. 1, U. S. Oeol. Borrey, 1900, p. 447. 

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luTgical difficulty was not overcome and the mine has been closed 
since about 1905. The dump shows a variety of andesites in the 
country rock and the ore seems to be a soft iron-stained rock which 
is probably andesite porphyry altered and impregnated with iron and 


The largest group of mines and prospects in the upper valley of Crow 
Creek is located on Eagle Creek in sees. 21 and 26, T. 7 N., R. 1 W. 
A number of these, including the Mammoth, Peter the Great, Jumbo, 
Toronto, and Blue Granite claims, are closely related to a small 
intrusion of diorite or gabbro in the andesite porphyry country rock. 
Some of the prospects appear to be on lodes of pyritized porphyry and 
some are on quartz veins. The ores include iron and copper pyrites 
ajid galena, some of them being of value principally for gold and 
others for silver. Ore from one of these properties is said by the 
owner to net $56 a ton, including 2 ounces of gold. 

In the valley of Crow Creek, besides the mines of Ea^e Gulch 
already noted, there are a few scattered claims worthy of men- 
tion. The first of these is the Sadie S. claim, on Slim Sam Creek, in 
sec. 28, T. 6 N., R. 1 W. This claim, which has been developed by 
six test pits and a tunnel about 30 feet long, seems to be related to a 
small intrusion of granite in impure limestone. Between the granite 
and the impure limestone there is a coarse-grained rock composed 
almost ^olly of crystals of green garnet. The ore, which rests on 
the mass of garnet, is a decomposed iron and copper stained quartz. 
An assay made by the United States assay office at Hielena dbows 0.60 
ounce of gold and 3.9 ounces of silver to the ton. In sec. 20 of this 
township are two claims known as the Silver Reef and Buena Vista. 
The Silver Reef is developed by a shaft 50 feet deep, undercut by a 
tunnel about 75 feet long. The vein, which consists of white quartz, 
is said to be 14 inches wide in the bottom of the shaft and to carry 
2.98 ounces of gold to the ton and a Httle copper and lead. Pieces of 
ore picked up around the shaft and probably derived from this vein 
assayed less than half an ounce of gold and 200 ounces of silver to the 
ton, according to the United States assay office at Helena. The 
Buena Vista claim lies about 250 yards south of the Silver Reef and 
is on a blanket vein in white quartzaite developed by shallow pits. 
The quartzite lies nearly flat, dipping only slightly to the west. The 
ore, which shows some copper stain, assayed at the United States 
assay office at Helena 320 ounces of silver and 0.01 ounce of gold to 
the ton. 

The Bonanza mine, in sec. 24, T. 6 N., R. 2 W., on the divide 
between the head of Johnny Gulch and the South Fork of Crow 
Creek, consists of about 10 tunnels on veins in limestone. The ore 
seems to be on the bedding plane, which dips 25^ N. It is mainly 


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galena canyiiig some impure sphalerite. The principal value is in 
silver. No work was being done here in the summer of 1910. One 
mile west of this locaUty, on the divide between the heads of the 
South Fork of Crow Creek and Sand Creek, there are several pros- 
pects in quartzite and in limestone on the top of a bare knob. Sev- 
eral pits and trenches show iron-stained quartz veins, but only a 
small quantity of ore is visible. That at the Summit claim is sili- 
ceous rock with a few grains of hematite and a little copper stain, 
having the general appearance of a gold ore, but it assayed only a 
trace of gold and 0.5 ounce of silver to the ton. Small pieces of 
pyrite and galena were found at a shaft by the upper cabin 50 yards 
west of the Summit claim, mixed with brecciated limestone cemented 
with quartz. This ore probably carries several ounces of silver to 
the ton. 

On Crow Creek in T. 7 N., R. 2 W-, placer ground has been worked 
m the canyon below the mouth of Wilson Creek and as early as 1858 
extensive placer mining was done on the head of Wilson Creek. The 
headwaters of Big Ticer Creek, just north of Crow Peak, also have 
been the location of gold-placer operations. Prospects in sec. 22, on 
the hill between Big Ticer and Wilson creeks, have been opened by 
George Dunges. Several pits have been sunk here in andesite por- 
phyry on iron-stained quartz veins which have the appearance of 
gold ore. A tunnel was being driven in 1910 to undercut one of the 
veins and was at that time about 150 feet long. One sample taken 
here assayed a trace of gold and 1.3 ounces of silver to the ton, and 
another carried 0.30 ounce of gold and 1 ounce of silver. About a 
mile north of Wilson Creek, on the trail leading to the divide at the 
head of McClellan Creek, there are two shafts and several small pits. 
The country rock on the north and west is coarse andesite porphyry 
and on the south and east is fine-grained andesite, in part finely 
porphyritic. Between these there is a narrow belt of aplite in which 
are zones of crushed altered porphyry cemented with quartz and iron. 
A sample of this crushed material taken from a few tons in the shaft 
house is reported by the United States assay office at Helena to carry 
0.40 ounce of gold and 2.1 ounces of silver to the ton. 

The Center Reef mine of Ballard Bros., in sec. 33, T. 7 N., R. 
2 W., on the head of Little Ticer Creek, is the principal operation in 
the upper Crow Creek vaUey. This mine is on a siliceous gold- 
bearing vein along a vertical crushed zone in andesite. The vein 
has been developed by two or three shafts and a tunnel 200 feet long 
driven to undercut it. Ore has been shipped from this mine for the 
last five years, some of it running as high as $225 a ton. The prin- 
cipal value is in gold. Four men were working here in August, 1910. 
Half a mile southwest of this mine is the Black Jack claim, which has 
been developed by one 60-foot and two 30-foot shafts. So far as 


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known no values have been obtained here^ but the claiin is interest- 
ing as it is located on a mass of brecciated andesite 75 feet in diameter, 
carrying a large amount of rusty quartz and radiating black crjrstals 
of tourmaline. 


The mines in Keating Gulch are in the Cedar Plains mining dis- 
trict near Radersburg, which is located at the mouth of the gulch 2 
miles east of the Keating mine. Under this heading will be men- 
tioned only those mines and prospects within a mile or so of the 
Keating mine. Only a very short examination was made here, 
because of the perfectly apparent mineral character of the land. 
There are scores of prospects in the vicinity, many of which show 
more or less ore, but they are so numerous and so small that it was 
not possible to visit them in the time allowed. All that was required 
in this examination was to determine the mineral or nonminera 
character of the land. 

Mining began at Radersburg about 40 years ago, when gravels west 
of the town were worked as placers and several hundred thousand dol- 
lars in gold was recovered. This led to prospecting for lodes, and 
quartz mining b^an about 1870. The principal lode mines are along 
a north-south belt of veins close to the Montana principal meridianl 
2 miles west of Radersburg. Oxidized ores were mined at a num- 
ber of places within a radius of 1 mile and amalgamated after crush- 
ing in crude arrastres. Sulphide ores were encountered at a depth 
of about 100 feet and this retarded mining activities for a number of 
years, but in the last year or so there has been a revival of interest 
and 150 to 200 tons of ore a day was being shipped in the later part 
of 1910. The ores are in narrow fissure veins having a north-south 
course and steep westward dip. They occur in andesite porphyry 
and consist of quartz and calcite gangue with principal values in 
auriferous pyrite. Other minerals occurring less commonly are 
chalcopyrite, marcasite, pyrrhotite, galena, sphalerite, and chal- 
cocite. In some parts of the district Tertiary lake beds mask the 
bedrock. Hot-spring deposits of tufa found in these unconsohdated 
clays carry traces of gold and in a number of places seem to cap and 
be the upper continuation of the fissure veins in the andesite. This 
suggests the possibility that the hot-spring deposits are the latest or 
final stage of mineralization.^ 

The Keating mine, which is the largest in the Radersburg district, 
is developed by a 300-foot vertical shaft and a 600-foot incline. On 
the 400-foot level a drift has been run north along the vein for a full 
1,000 feet and south for 1,200 feet, making 2,200 feet on this one 
level alone. The vein is from 2 to 4 feet wide. About 100 men are 

1 Bard, D. C, Geolosy of the Radenlnug distcicti liontaoa: Jour. Asboc. Eng, Soc, vol. 46, No. 1, July, 
mo, pp. 14-17. 

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employed. In October, 1910, about 100 tons of ore was being shipped 
daily, areraging S19 a ton, and in December the mine was shipping 
about 2,100 tons a month, areraging S24. The value is mostly in 
gold. Some ore taken recently on the 400 and 500 foot levels carries 
17 per cent of copper. There is a small value also in silver. 

The most conspicuous ore on the dump is a highly pjrritized rock 
having the appearance of gray quartzite and called by the miners 
''porphyry." A thin section of this rock, which is mineralized wall 
rock, shows that it is a porphyry, composed of a fine glassy ground- 
mass with niunerous fragmental feldspars altered to sericite. Pyrite 
and quartz are secondary. 

The Ohio-Keating mine, about 2,200 feet farther west, on a vein of 
similar ore, has a shaft 220 feet deep and several levels. The lower 
100 feet of the shaft is said to be all in ore averaging S16.25 a ton in 
value. Farther up Keating Oulch are the Hard Cash mine, which is 
developed by two long tunnels on auriferous pyrite-bearing quartz 
veins, and the Kahoka claim, which has a 70-foot shaft and several 
pits on a vertical vein 2 to 3 feet wide consisting of quartz staiaed 
with iron and malachite and probably carrying a little gold. 

About three-fourths of a mile north of the Keating mine, just east 
of the range line, is the Radersburg Kena mine, on ore similar to 
that of the Keating mine and in pyritized porphyry. This mine was 
being actively developed and nine men were employed in September, 
1910. Just west of the Rena mine there is a considerable number of 
small shafts and pits on north-south lodes in andesite, ore from one 
of which was milled in an arrastre. 

The Black Friday mine, which is situated about a mile southwest 
of the Keating mine, is similar to it geologically. It has a 500-foot 
shaft and about 1,900 feet of levels. The mine produced over 1,150 
tons of ore between June, 1909, and August, 1910, and the ore is 
reported by the superintendent to average $50 to the ton, mostly in 
gold, with 1 to 2 per cent of copper, a little silver, and no lead. 


The first mine encountered in going up Johnny Oulch is the 
Simpson, on the Cyclone claim. It is located about half a mile due 
souUi of the Black Friday mine, near the North Home mill. The 
Simpson mine has several hundred feet of underground workings, 
including a deep shaft and a long tunnel. It is on a vein of pyritif- 
erous free^milliog gold ore, which was treated in a stamp mill on 
the property. This mine was idle ui 1910. 

At the head of the gulch on which the Simpson mine is located, 
1 ,000 feet west of the Black Friday mine, is the Bluebird. In October, 
1910, a new shaft had reached a depth of 60 feet on a 4-foot vein of 

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yellow porphyry and iron-atained quartz. The ore is gold-bearing 
porphyry like that at the Black Friday mine. 

On the south of Johnny Gulch is Cable Mountain, on which there 
are a score or more of prospects and small mines, and also Monterey 
Hill, a highly mineralized butte in which many of the prospects have 
found more or less copper ore. These two hills are all in andesite por- 
phyry, carrying nuuMious vertical Tsins which strike in all directions. 
AmoBg the small mines are the Monterey No. 1, which has an 80- 
foot shaft and a 180-foot crosscut, said to be all in low-grade iron 
ore carrying Uttle bunches of silver and copper. The Key West and 
Keystone or Iowa mines have pyritiferous ore canying both gold and 
copper; the latter is said to have a 150-foot shaft and a 600-foot 
tunnel, but they are now caved. 

About 3 miles up Johnny Gulch from the North Home null is the 
North Home mine, which has about 450 feet of shafts and tunnels 
in a silver-bearing vein in highly tilted Madison limestone. From 1 
to 2 miles north of this mine, in a body of granite intruded in the 
Jurassic and Cretaceous beds, Uiere are a number of prospects and 
small mines in and around the granite which show promising ore. 
Among these are the mines owned by George Horn and John Roth- 
fus on the road up Keating Gulch. These mines on the contact 
between granite and more or less calcareous beds show, besides a 
considerable amount of garnet, an ore carrying various copper carbon- 
ates and at one prospect at least, some free gold. On the south 
side of Johnny Gulch, along the hogback ridge made by the Quad- 
rant formation, there are a number of prospects worthy of mention. 
The first of these is the Mount Shasta claim, in the upper part of the 
Madison limestone. Samples of galena ore assayed 32 ounces in silver 
to the ton according to a report fron the United States assay office at 
Hel^ia. Half a mile south of the Mount Shasta claim, on top of the 
quartzite hogback, is a claim belonging to C. C. Smith on an east- 
west vein which dips 85® N. and is about a foot wide. The ore is 
mainly iron and galena and carries in the porous part of the vein 
numerous orange-colored crystals of wulfenite Goad molybdate) and 
a small amount of barite. Farther south along this line of hog- 
backs and north of the Ruby mine are the Daisy, Santa Clara, Silver 
Nuget, and Diamond lodes, all developed by small shafts and showing 
gold, silver, lead, copper, and iron ores. The Ruby mine, in sec. 33, 
T. 5 N., R. 1 W., was developed by two large 45° slopes and shipped 
a large amount of ore, the principal value in which was gold, with 
some silver and lead. Other prospects and small mines in this 
vicinity are too numerous to mention except the old iron mine in the 
southeast comer of sec. 20, which was worked many years ago and 
is said to have shipped for flux thousands of tons of iron ore that 

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carried about $1 a ton in gold. The ore on the dump shows a little 
malachite. There were probably about 1,000 feet of underground 
workings on this ore deposit, which seems to be on or near a contact 
between limestone and intrusive andesite. Farther up Johnny 
Gulch, in sec. 18, are the Silver Bell, Ned, and Globe mines, in lime- 
stone and near a thick porphyry intrusion. It is said that 1,000 
tons of ore from the Silver Bell mine was sold on the ground for S106 
a ton and hauled to the Wicks smelter. These are all silver-lead mines 
carrying a little copper. Near the head of Johnny Gulch is the Spar 
mine, which has a shaft probably 100 feet deep, now caved, and a 
slope nearly 200 feet long in limestone on a calcite vein carrying 
silver, lead, and copper. This mine is near the axis of the anticline. 


The Elkhom is the principal mining district in the Elkhom Moun- 
tains and is reached by a triweekly train on the Northern Pacific 
Railway or by stage from Boulder. As abready stated, it is the 
subject of a detailed report by W. H. Weed, and for this reason it is 
not necessary here to describe the ores or their occurrence. It is 
sufficient to say that through an area of highly tilted limestone and 
quartzites there have been injected gabbro and diorite and later 
granite, which have metamorphosed the sediments, and that the fol- 
lowing mineralization resulted ia the deposition of considerable 
bodies of ores of gold and silver. The Elkhom mine, which has been 
one of the largest silver producers in the country, is on silver-bearing 
calcite ore shoots between a homstone hanging wall and dolomite 
footwaJl. Up to 1900 this mine had produced 8,902,000 ounces of 
silver, 8,500 ounces of gold, and 4,000,000 pounds of lead. It waa 
then considered worked out, but has since been bought by successful 
mine operators, who, after expending two years' time and $60,000 to 
$80,000 in pumping out the water, have again put it into operation. 
In the summer of 1910 between 75 and 100 miners were employed. 
The onjy other mine in the district actively producing at the same 
time was the Golden Curry, which was originally developed by tun- 
nels on a mass of iron ore, apparently a mixtmre of hematite and 
limonite, occurring on the contact between granite and Cambrian 
limestone. The tunnels caved and the ore is now taken out by the 
open-pit method. In July, 1910, according to the manager, John 
Rothfus, this mine was ^pping 20 tons of iron ore daily, which 
averaged $35 a ton in gold and 2^ per cent of copper and went to the 
East Helena smelter for flux. At the time of the writer's visit a 
block of copper ore about 2 feet in diameter was found in the midst 
of the limonite which carried besides malachite a small amount of 
native copper. 

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The C & I> mkub ku pvoduowl sereral thousand dollare in gold and 
silver ftron ain mr^ body in marbkised Madison Kmestene near a 
granite eoatacL Altar being idle for many years it was prospected 
again ia 1S10, but the writer uBdentands tiiat altw a few months of 
unsuccessful explcratioft operations ceased here. The mine has a 
shaft 250 feet deep with several levels and a crosscut through the 
limestone to the granite contact. Other mines in this district are 
the KeenO; Dolcoath, Midnight Bell, and Queen. On the north side 
of ElkhcNnot Peak tkero is aa iron raise en a contact between andesite 
and laarhlB from which a ceasiderable quantity of ore has been 
shipped to smelters for flux. The ore is akM^ the bottom of the 
marbb mass and is probably a replacement of it. It is a flne- 
grained mag&etite siMwing grains of ebahK^yrite and garnet. Mala- 
chite IB found on the weathered ore. It probably carries small values 
in gold. 

South oif Elkbimi vahiaUe minerals have been found at several 
places, but only a few of them wfll be m^itioned. The Queen mine, 
2 mike due south of Elkhon, i^ears to be on a north-south quartz 
vein of considerable width and dippnug 80^ E. The vein, which is 
said to be 24 feet wide, has a limestone footwall and porphyry hanging 
wall. It was developed by a deep vertical shaft and by a slope, both 
with levels. The slope is now caved to an open pit, showing the 
great width of the ore body. The ore is quartz carrying pyrite. It 
was sorted by hand, and the appearance of the bins suggests that a 
considerable quantity was shipped. It is reported that during May 
and June, 1900, more than 1,000 tons of ore was shipped to East 
Helena. Although the quantity of ore is large, the values are low. 
The boilers, hoisting engine, cage, skips, etc., are all in place, although 
the mine has not been operated for several years. 

In the bottom of the gulch just east of the Queen mine a 100-foot 
tunnel has been driven on a galena-bearing quartz vein between a 
porphyry footwall and limy shale hanging wall. At the head of a 
side gulch half a mile north of the Queen mine there is a series of 
tunnels on the contact between a porphyry footwall and limestone 
hanging wall. The ore is said to carry a little lead and sflver; low- 
grade copper carbonate ore was found on the dump. 

The Tacoma mine, which consists of ten tunnels and pits on or 
near the contact between andesite porphyry and Cambrian lime- 
stone, shows galena ore and is said to carry values in gold and silver. 
All the openings were caved in 1910 except one in which two miners 
were working. This tunnel is in porphyry and shows a flat-lying 
siliceous vein 1 to 4 inches thick carrying lead carbonate. 

The Leroy quartz lode is situated on the top of a ridge at the end 
of a graded road about three-fourths of a mile southeast of the 

94174**— Bull. 470—11 7 

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Tacoma mine. It is a vertical vein 2 to 3 feet wide having a N. 25^ E. 
course, in limestone which strikes S. 50° E. and dips 30° to 48° SW. 
The vein has an iron cap. It has been developed for 100 yards by 
five pits and timnels, and an ore bin was built but never used. A 
sample sent to the United States assay office at Helena contained a 
trace of gold and 5.3 ounces of silver to the ton. 


In the foregoing pages it is shown that mineral deposits of con- 
siderable value have been mined at a number of places in the Elkhom 
Mountains and that active mining operations are now being carried 
on at two places, at Elkhom and at Keating Gulch, near Radersburg. 
Ore deposits in these mountains occur on contacts between granitic 
rocks, such as granite, gabbro, and diorite, and intrusive and ex- 
trusive volcanic rocks and sedimentary formations; they occur also 
as fissure veins in the granite area and in the andesite porphyry and 
as replacement deposits in limestone. 

In the Pennsylvanian limestone phosphate rock may possibly be 
found. Specimens of float collected by the writer in the valley of 
Slim Sam Creek analyze as high as 27.29 per cent of PaO,. 

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By J. M. Hnx. 


During a part of July iand August, 1910, the writer examined cer- 
tain lands in the White Horse or Olinghouse district, Washoe County, 
Nov., on which suit had been brought by the Department of Justice. 
After the completion of this examination a few days were spent in 
visiting the other mines in this district and those in the Ramsey and 
Talapoosa districts of Lyon County. 

The writer is indebted to the mine operators in these districts for 
their consideration and assistance, particular thanks being due to 
Mr. J. A. IngaUs, of Reno. 


The White Horse or Olinghouse district lies on the east side of the 
Virginia Range, north of Truckee Canyon. It nominally includes 
Tps. 21 and 22 N., R. 23 E. of the Mount Diablo principal meridian. 
In reality the productive area covers about 6 square miles located 
about the town of Olinghouse (1, fig. 9), at the south end of the 
district, 9 miles west-northwest of Wadsworth and about 7 miles 
northwest of Derby, stations on the Southern Pacific Railroad. 

Ramsey (2, fig. 9), a town of about 100 inhabitants, is 17 miles 
southnsoutheast of darks station, on the Southern Pacific RaUroad, 
with which it is connected by a good road traversed daily by a mail 
stage. It is in Lyon County, near the center of a basin about 3 
miles in diameter on the southeast flank of the Flowery Range, a spur 
of the Virginia Range. The principal mines, the Ramsey-Comstock, 
Ramsey, and San Juan, are north of the town. To the south there 
are several prospects at which more or less work has been done. 

The Talapoosa camp (3, fig. 9) lies in a small valley 14 miles south 
of the new town of Femley, on the Southern Pacific Railroad, and 
5^ miles northwest of Hawes siding, on the Tonopali branch of the 
Southern Pacific. There are several prospects of minor importance 
in this camp and one, the Justice, at which a larger amount of work 
has been done. 


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The northern part of this area, as far south as latitude 39^ 30' 
north, was covered by the geologists of the Fortieth Parallel Survey, 
is shown on their aUas, and is discussed in detail in their report.^ 
The region is largely undeiimn by Tertiary volcanic rocks, except 

for small isolated areas of prevolcanic rocks and the valleys that are 
covered with silts and gravels of Quatemajy ageu 


Northward from Wadsworih, in the Pyramid Lake Indian Reser- 
vation, Truckee River has cut deeply into soft thin-bedded sand- 

I King, Clarence. U. 8. OeoL Expl. 40th Far., Atlas sheet fi; vd. 2, 1878,pp. S17-844. 

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stones of buff to gray shades, fuUj described bf Kisg as Plioeene.^ 
These beis am m turn cov«red by Quatoimafy gcavels and aitla. 

About 4 mfles sooth of Rausey oft tbe reaid to Dajtem thei* is a 
smatt area ef pooily escpoaed dark Ain-bedded Unestone and diales. 
No foflsAi irere found in this leeelity, ao tlw age of tbs.TXK^ is not 
known. They ai« oapped by andeaiito and ibyolite, ha^9«vtf, and 
are therefore pre-Tertiary. 

Near Steamboat Springs, in a portion of the region net Tiritod by 
the writer, is a series cf metasiorphoaed sediBientary bads of Mommc 
age that hare been laapped and deacribed by Bedcer,' 

The fourth localily in which tbwe aM aediEmentery rooke is in the 
head of Long VaMey, ait the CSialk HiIIb randi, whero diere is a bed 
of diatomaoeons earth imierbedded with rhyolitie and andeailac til£b| 
capped by basak. 

Oranodiarite. — Granitic rocks are exposed at only one locality in 
the area tinder discussion, about 3^ miles south of Ramsey. The 
rock is coarsely granular, much weathered, and of a light-gray color. 
It consists of quartz, orthoclase feldspar, plagioclase feldspar, and 
biotite, and should probably be classed as granodiorite. This forma- 
tion is marked by a low, rounded topography in contrast to the jagged 
forms of the lavas. The area underldn by the granite is smaD and 
the relations are not at all clear. The rods: appears to be intrusive 
into the dark thin-bedded sediments, though tUs is not certain, and 
is capped by Tertiary lavas. 

01^ aniesite. — The oldest Tertiary lava of this region is a dark- 
purple, green, or brown, in places tuffaceous andesite, exposed best 
on the east side of the Olinghouse district (1, fig. 9), where a fault 
has tilted the flows to the west-eoufhwest at low angles. Bussell 
shows this fault line in his report on Lake Lahontan.' The andesite 
is fine grained, but the individual crystals can usually be distinguished 
with the pocket lens. Under the microscope the slides examined, 
though not fresh, showed the rock to be a typical andesite porphyry. 
The phenociysts of andesine and hornblende are set in a groundmass 
composed of minute crystals of andesine or oligoclase and a small 
amount of magnetite and hornblende. In one slide a few roimded 
grains of original quartz were noted, showing a tendency toward 
dacite. This tendency is particularly well shown in the region south 
of the town of Ramsey (2, fig. 9), where blebs of quartz up to one- 
fourth inch in diameter are rather prevalent in the rocks. 

S^yoliU. — ^The andesite is cut by dikes of a lighlr-colored rfayolitic 
rock which also caps the older rock. Just east of Washington camp 

1 Klnc, ClaraDoe, op. dt., pp. 817-S24. 

s Bedker, O. F., Geology of the qnlckailyer deposits of the Paciiio slope: Hon. U. S. OsoL Sonrey, voL la, 
1888, pp. 833-334. 
•Biasell, I. C, Geological history of Lake Lahontan: Hon. U. S. GeoL Buryey, yoL 11, 1886^ PL XL 

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(4, fig. 9} occuis the most typical rhyolite flow seea during the 
recoxmaissaace. The rock is gray in color and shows thin-bedded 
fluidal structure; the flow is at least 350 feet thick. The more usual 
occurrence of rhyolite in the region is in the form of dikes yaiying 
from a few feet to several hundred feet in width. The smaller dikes 
are apt to be confused with silicified bleached andesite, which occurs 
in the vicinity of the mines. 

At the mouth of Fort Defiance Canyon (Berkshire Canyon of King ?) 
there is a lai^e white hill composed of a coarsely porphyritic to 
granular rock, which is probably a phase of the acidic intrusion. The 
rock consists of orthoclase and quartz with ahnost no ferromagnesian 
minerals. The slide examined would be called alaskite porphyry, but 
in the mass of the rock there is sufficient dark mineral to make it a 
granite porphyry. This large mass appears to grade out on both 
the north and the south into finer phases and finally into dikes of 
rhyolite porphyry. 

Later andesite. — Dikes of a very fine grained dark-gray to black 
rock cut both the older andesite and rhyolite of the region. These 
dikes are composed of trachytic andesite in which the phenocrysts 
are small and rather scarce or entirely lacking. Where present the 
phenocrysts are andesine, hornblende, and augite. In some slides 
the augite prevails, making the rock an augite andesite. In only 
one slide was biotite surely determined, though its presence in others 
was indicated by aggregates of chlorite and magnetite assuming the 
form of biotite. 

The cap rock of the mountains north of Truckee Canyon and west 
of Olinghouse is a reddish-gray porphyry with distinct phenocrysts 
of biotite and plagioclase feldspar. King * has mapped this forma- 
tion as trachyte, and Hague and Iddings ' describe these rocks as 
homblende-mica andesites. The single thin section from specimens 
taken by the writer contains phenocrysts of cinnamon-brown mica, 
plagioclase feldspars with beautiful zonal growth ranging from oligo- 
clase to andesine, and a white mineral whose index of refraction is a 
little less than that of Canada balsam and which may be either ortho- 
clase or sanidine. The groundmass of this rock is much altered but 
is apparently composed of glass with some few crystals of plagioclase 

Bdsalt, — ^The greater part of the area shown on the sketch map 
(fig. 9) is covered by vast flows of basalt which range in color from 
black through chocolate-brown to gray. The groundmass of this 
rock is glassy and vesicular. In this glass base there are fragments 
and crystals of plagioclase, hornblende, augite, and oUvine, with 

^ King, Clarence, IT. 8. Qeol. Ezpl. 40th Par., Atlas sheet fi. 

* Hague, Arnold, and Iddings, J. P., On the development of crystalllxatton in the (gneoos rocks of 
Washoe, Nov.: Boll. U. 8. Qeol. Surrey No. 17, 1S85, pp. 28-24. 

Digitized by 



scattered specks of biotite. The compositLon of the basalt is not at 
all constant. South of Truckee Canyon olivine is absent or is present 
in very small amounts and the rock is lighter colored than at the 
head of the canyon, where typical black olivine basalt is exposed.^ 



The Talapoosa ore deposits are said to have been worked in a smaU 
way as early as 1864 by prospectors from Yiiginia City, but so far as 
can be learned there has been no production from this camp. 

The town of Ramsey was built in 1906, after the excitement caused 
by the opening of the Ramsey-Comstock ore body. Prospectors from 
Virginia City are said to have located this property in the late sixties, 
but no work was done until the beginning of the twentieth century. 
The production of the camp so far has come from one mine and is 
said by the operators to be $80,000 gross. 

The White Horse or Olinghouse district was first prospected in 
1860, and locations were made in Fort Defiance Canyon in 1864. In 
1874 the Green Mountain mines at Olinghouse were located by Frank 
Free. The geologists of the Fortieth Parallel Survey make no mention 
of Tnining in this vicinity, though they give sections along Truckee 
and Berkshire (Fort Defiance ?) canyons.' 

The period from 1901 to 1903 witnessed the greatest activity in 
the camp, three mills running most of the time. In July, 1910, 
there were four mines in the district at which work was being done, 
and two small mills were taking care of the ore. 

The placer and deep mines are estimated by Mr. J. A. Ingalls, 
of Reno, an operator in the district, to have produced from 1897 to 
the present time about $775,000. Statistics collected by the United 
States Geological Survey for the period from 1902 to 1909, inclusive, 
give the total production of the district at $235,671, of which about 
99 per cent was gold and 1 per cent silver. 


On the sketch map (fig. 9, p. 100) the areas in which the mines and 
prospects are located are indicated by dark stippUng. They occupy 
depressions, usually of erosion, from which the basalt capping has 
been removed, thus exposing the older volcanic rocks. It is not 
meant by this that in all places where the andesites and rhyolites are 
exposed there are prospects, as the productive areas are those in 
which these rocks are much altered. The later andesite intrusion 

> King, Claranoe, U. S. GeoL BxpL 400k Fw., voL 1, 1878, pp. 676-077. 
s Ideza, vol. 2, 1870, pp. 817-8M. 

Digitized by 



appears to have had tke most marked effaot a&d to be the oaiue of 
most of the ore depoeits. Where the older andeeite and Ayottte are 
cut bj dikes of this younger andesite they are vsually leached, hayii^ 
a white to gray-green earthy appeerance. At some places along 
the dikes they have been silicified and the resulting hardened rock 
resists erosion longer than the surrounding formations. This siUcifi- 
cation was noted in all the districts but is strongest at Ramsey and 

Ore occurs in quartc veins but more conunonly in ledges of altered 
silicified country rock somewhat sknilar to the ore bodies at Goklfield 
described by Ransome.^ Dev^opments have se far hardly pene- 
trated to wat^ level, and as a oonseqiAence the ores are all oKidtzed. 
Free gold and probably a little silver chloride are the only valuable 
min^als; though chaloopyrite was noted at the Justioe mine at 
Talapoosa, and pyrite is always present in the ore. Tellurium was 
determined by E. E. Buxlingame, of Denver, in high-grade ore from 
the Buster properties at Olingbowe but was not noted elserwfaere. 


(kUline of geology. — ^The prevalent formation in the Wlute Horse 
district is the older andesite. The eastern lulls eossist of green to 
purpli^-brown flows dij^fMog west-southw^atward at low angles. 
They are in general rather fine grained porphyries, but sevend of the 
beds are tuffaceous. Porphyrttic riiyoUle and tiie later andesite 
intrude tiiis thick series as sills and dikes. The rhyolite is confined 
largely to the area east and noirt!k of tim town of Olii^jKHise; the 
later andesite is found all over the district but is most abundant on 
Green Hill, just north of the town. The principal mines are located 
within a radius of l^ miles of this hill, which seems to be the center 
of the andesite intrusion. 

Green HiU mines. — ^The Gold Center, Butte, and Don Dero mines, 
located on the southeast flank of Green Hill, are r^<Mrted to have 
been large producers of high-grade ore. They were not being worked 
in 1910 and could not be examined. The dumps of the lower tunnels 
are extensive, and a number of shallow pits and shafts are scattered 
over the surface. The ore is reported to have been largely quartz 
and calcite, with free gold occurring in pockets along a zone of soft 
altered andesite which in places showed slickensided surfaces. 

Eeygtone-Nevada mine. — ^The Keystone-Nevada mine is about 
three-fourths of a mile northwest of Olinghouse, in a small side 
canyon. The coimtry rock is the older andesite, which is cut about 
a quarter of a mile north of the mine by a dike of rhyolite. The ore 

1 Ranaome, F. "L., PreUmlnaiy aoeotmt of Ooidfield, Bullfrog, aod other mininf districts in sonthem 
Nevada: BuU. U. S. Oeol. Survey No. 303, 1907, pp. »-34; Itie geoltfgy Mid oK deposits of Goldfleld, 
Nevada: Prof. Paper U. S. Oeol. Survey No. W, 1900, p. IGO. 

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body conmto of two tabolir aiMaes ctf breectated flilieifi«d tndente 
havmg th« form of Tettu "wliicli strike i. few d egrew Mst of north 
and dip at about 65"^ to 80^ W. Tbia body vmBgm from a few imkm 
to BeTBtal feet in thioknen aad is nwde up largely of Mtteky qwutta 
with afewfragm^its of theeflioafted andesito. Pyrite ia disseiDi&ated 
tftaroughoiit tUs masa and a liMle free gold is aeen in eome epeoinMna. 
The rein has been fraetvured and the spaces fiMad with ^f^te quarts 
and calcite, neither of which apparently ooDteins any m^aUic 

Tlie property ia developed by two tusnels on the hangkig and 
foot waUa and several shafts. Most of the ground in the hanging 
vein aboTe the Umnel le-rel has been stoped. Between the fostwall 
and hangin^wali ymub there is a horse of somiMrhat silicified aadesite, 
with some pyrite dissemkxated throughout. The twx> Yeins apparantly 
diverge with iaoreasing depth. 

The nuBe, which is worfaed under lease, is produoi^ tiaily aibeut 
7 to 8 tons of (»« that is said to ran from $15 to 140 a ton. The ores 
are treated at the Slip mill at Olinghouse. The crushing equ^ment 
consists of two 3^oot Huntington aoiUs driven by a gaseliQe engine, 
and the values are saved on amalgamation phites. 

Tiger group. — ^The Tigcs* group is located near the head of Tigw 
Canyon, about a mile and a quarter north of Olinghouse. The 
country rock here is earlier andesite cut by a northeast-southwest 
dike of late andesite. The vein strikes N. aO^ E. and is almost ver- 
tical. It is a fault none along the contact of the countiy rock and 
the intetisive. The ore is quarts carrying pyrite and a minor mmonat 
of chaloopyrite. The development oonsifirta of a dOQ^oot tunnel and 
a shaft IfiO feet deep with drifts at the 75 and IdO foot levels. The 
drifts are entirely in the ^'vein/' the upper one being 6M feet and 
the lower one 780 feet long. It is said that the best values oocor in 
shoots pitching northeast in the vein and that three'of these have 
been cut in each of the levels. No ore has been shipped. 

Buffkr mines, — ^The Bust^ mines are boated about If miles' 
northeast of Olinghouse, on the divide between Frank Free and 
Tiger canyons. The older andesite is here cnt by both rhyoKte and 
andesite. In the area covered by the ohims there are several nearly 
parallel north-south aones of alteration and sUicifioation. The 
primoipal ones are on the Maeina and Di^^ensia claama. They occur 
along a contact of older andesite and rhyolite near a dike of kter 

On the Maoiaa a tunnel about 150 feet long espeees a ¥ii& of 
drusy quartz from 5 to 20 inches in width, whioh strikes on an averi^ 
about north, though there are minor irregvlarities ia its eourse, and 
dips to the west at high an^es. The vein is clearly divisible into 
two parts. One, a rather massive yellow-stained quartz, is said to 

Digitized by 



run as high as S80 a ton. This usually follows the footwall and is 
from 4 to 8 inches wide. The rest of the vein is white drusy quartz, 
stained yellow in places, and runs from $5 to SIS a ton. A 75-foot 
winze dipping 60^ to 75^ E. runs out of ore about 20 feet below the 
tunnel level, but it is said that since the writer's visit an 18*foot 
crosscut to the west about 25 feet below the tunnel has exposed the 
vein.^ The lower part of this winze is in very soft, much decomposed 
altered andesite, showing the action of hot water. 

On the Dispensia claim an irregular incline pitches to the west in 
soft altered andesite. From this andesite was taken, it is said, a 
very rich kidney of ore, which assayed as high as $4,000 a ton in gold 
and silver. The ore had been entirely removed from this pocket in 
August, 1910, but a sample said to have come from this place is a 
brownish-yellow heavy mass, consisting of fragments of sericitized 
andesite, cerusite (?), argentite, and possibly a telluride of gold and 
silver. This yields gold in the pan, and a sample assayed by 
E. E. Burlingame & Co., of Denver, gave as high as 1 per cent of 

Several other tunnels and shafts show a zone of crushed altered 
andesite about 20 to 40 feet wide to be mineralized, and this is said 
to carry from $2 to $4 a ton in gold and silver. 


OvMiie of geology, — ^The Ramsey district (2, fig. 9) occupies a 
basin, from which the basalt capping has been removed, exposing 
the andesites and rhyolites. The northern part of this basin is 
underlain by rather coarsely porphyritic andesites, some of which 
contain quartz blebs. There is very httle rhyolite in this part of the 
district, though a few small dikes were noted. The hills forming 
the southern limit of the district are made up of rhyolite of light-buff 
shades, apparently in large part flows. 

About a mile north of the town an east-west fracture zone, marked 
by intense silicification, runs across the basin. This ' 'dike'' is stained 
a dull brownish red and stands well above the surroimding andesite. 
In the field this body has the appearance of a rhyolite dike. Slides 
of the rock show it to be entirely quartz, and there is no clue as to 
whether it was originally andesite or in reality a rhyolite dike. 

Ramsey-Comstock mine. — ^The ore body of the Ramsey-O>mstock 
mine lies in this ''dike." The development consists of a 400-foot 
shaft dipping 57° to 60® N., which is on the footwall of the dike at 
the surface but 90 feet south of the wall at the 400-foot level. Below 
the 60-foot level the dike is much shattered. Two series of joints 
cut it in northeast-southwest and northwest-southeast directions. 
Pyrite is disseminated throughout the quartz mass but is particularly 

1 Letter from J. A. lo^allt. 

Digitized by VjOOQIC 


abundant on the hanging-waU side of the joints running northeast. 
The general tenor of the dike is said to be from $6 to $10 a ton, but 
in the lenses on the northeast joints the values are said to run up as 
high as S50 or $100 a ton. The dike at the 200 and 400 foot leveb 
is about 40 feet wide. The hanging wall throughout is marked by a 
fault zone on which there is from 5 to 15 feet of greenish-black clay 
gouge composed of crushed andesite. This soft material grades into 
fairly fresh quartz-bearing andesite porphyry about 40 feet north of 
the hanging wall. Permanent water was encountered at a depth of 
120 feet. At 160 feet the ore was largely pyrite, with only here and 
there a showing of free gold. 

The surface equipment consists of a 32-hor8epower gasoline hoist. 
The mill is equipped with an EUspass crusher and two regrinders. 
The values are saved on amalgamation plates and three Gates tables. 
The concentrates are entirely of pyrite and are said to carry about 
$100 in gold to the ton. 

Ramsey shaft. — About 500 feet west of the Ramsey-Comstock 
shaft is the shaft of the Ramsey Mining Co. This was closed at the 
time of the writer's visit but is apparently on the same "dike" as the 

San Juan mine, — San Juan Hill lies about 1 J miles northwest of 
Ramsey, west and south of the road to Clarks. The main mass of 
this hUl is andesite, but this rock is cut by a dike or siUcified zone 
somewhat similar to that at the Ramsey-Comstock. The San Juan 
mine is located on the northwest side of the hill. It could not be 
visited owing to the absence of one of the partners, the other not 
being willing to allow anyone to examine the property. It was said 
that some very rich specimens had been taken from the 150-foot shaft. 

Offier prospects. — ^The Best & Belcher prospect, IJ miles southwest 
of town, is in an 80-foot zone of somewhat altered andesite striking 
N. 17° E. A trench across this belt is said to have shown the values 
low but distributed about equally throughout the body. 

On the Spencer claim, 2i miles south-southwest of Ramsey, a belt 
of kaolinized quartz-bearing andesite near a dike of later andesite 
has been prospected by a 60-foot shaft and a crosscut. It is asserted 
that for a distance of 15 feet from the dike the altered country rock 
carrying pyrite has an average value of $5 a ton. 

The Qaravanta claims are half a mile south of the Spencer. Several 
rather long tunnels have been driven into altered andesite below a 
thick flow of rhyoUte. In one of these tmmels there is a fault zone 
striking N. 25® to 40** E., along which quartz, calcite, and gypsum 
occur in seams. It is said that some pockets of rich ore have been 
taken from this tunnel. 

One mile south-southeast of Ramsey, on the top of one of the 
rhyolite hUls, is the Hawks Nest prospect. The vein apparently 
strikes nearly east and west and consists of quartz. 

Digitized by VjOOQIC 


TAI.AP008A. DlffESIOa?. 

The Talapoosa district (3, fig. 9) has only one prospect of impor- 
tance — ^the Justice. The croppings of the vein are prominent, being 
vety hard. Rhjolite is here cut by an andesite dike about 150 feet 
wide, which can not be traced w^tward for over 200 feet, as it is 
capped by basalt. The dike dips 40® SW, Above the dike, to the 
south, the ''ledge'' is from 8 to 28 feet wide and consists of brownish- 
stained drusy quartz. A 650-foot tunnel is driven along the south 
side of the quartz ledge in soft altered rhyolite showing no mineraliza- 
tion. Several crosscuts are driven northward into the vein proper, 
which consists of bluish-gray quartz cut by stringers of white quartz 
and calcite. As far as noted only the dark quartz contained metallic 
minerals. These were pyrite and chalcopyrite, probably with some 
argentite and silver chloride. 


At Washiogton camp (4, fig. 9) there are a few prospects in much 
altered rhyolite cut by dikes of later andesite. No work was being 
done in this vicinity at the time of the writer's visit. The prospects 
so far as seen showed only stringers of calcite and gypsum. 


The Chalk Hills are about 9 miles aortheast of YizgiBia City, near 
the head of Long Valley. This region is one of low relief, beiiig a 
fairly level basin surroimded by basalt hills. The floor of this basin 
is also largely basalt, except along the wash, where it has been 
removed. Under the basalt there is a series of thick beds oi ihjolitic 
and andesitic tuff dipping north at low angles. Interbedded with 
these rocks is at least one bed of fine-grained white diatomaceous 
earth. This bed at the mine is folded with the tuffs. The body was 
formerly worked by open-cut methods, but lately a tumiel about 150 
feet long has been driven in on a level with the bottom of the pit, 
which is 100 feet long, 30 to 40 feet wide, and 40 feet de^. liie first- 
grade material is about 36 inches thick sjkd the whole bed is from 30 
to 40 feet thick. It strikes N. 60^ W. and dips 65** NNE. The 
better grade is broken separately, some brown stains on joints beixig 
removed with a hatchet cmd sacked. The poor^ grade can, by the 
liberal use of the hatchet, be made to yield about 40 p^ cent oi good 

It is said that the company operatmg the property ahips from this 
mine yearly from 7 to 9 cars of infusorial earth, which is used in the 
manufacture of electro-silicon. 

Digitized by 



By Sidney Paioe. 


Finos Altos lieo in northeastern Grant Ciountj, N. Mex., about 6 
miles northeast oi Sily^r City, which is reached by the Deming and 
Silver City branch of the Atchison, Tc^pAa & Santa Fe Railway. A 
narrow-gage railroad and good wagon roads afford connection with 
Finos Altos. The town is litnated an the eastern slope of the Finos 
Altos Mountaina at an ekration of about 7,000 feet. 

At the time of the writes visit only one deposit of the fissure-vein 
type was accessible, and that only in part. A brief histocy of the 
disiciet and an account oi the geology and mines, by L. C. Graton, 
waa published in 1910.* The present paper contains a map showing 
the geologic relation of the ore bodies in more detail and brings 
together .what eould be learned of the inaccessible portion ei the 
veins. The inaccessible condition of the mines made original under- 
ground observations impossible. The mine dumps, however, were 
studied with some care and, though a systematic accoimt of the ore 
depofiilion can net be given, some information eould be gleaned from 
these aimrces. Acknowledgments are due to Mr. W. C. Chandler, 
both for much of the quoted information which follows and for the 
many eourtesies which he extaided to the writer. 

The rsi^laeement deposits known as the Cleveland gfoup have been 
more Mctensively developed since Graten's visit and additional data 
are therefore at hand regarding them. 



The geology of the Finos Altos district is simple. (See fig. 10.) A 
roughly elliptical mass of granodiorite intrudes a complex of diorite 
porphyry and associated dikes;' fissure veins have been formed in 
both masses and cut across their contact without interruption, and to 

1 UMcnSt W4dnMI»Qi»tB». L. G.,mlQn&p% C. H., T1ieM»d«potltsoflN«wMeadwK Profi Papor 
U. 8. a«oI. Svrvey No. 68, 1910i p. 297. 

ThB gnnodiorttB has been considered the oldest rock by prevlons workers (Piof. Paper U. S. OeoL Snr- 
▼ay No. 68^ im^ p. M), M tMr werk was «f araooouJssttioe utem. 


Digitized by 



the north trachytic and other lavas of later age than the veins cover 
the intrusive masses. 

Almost 2 miles northwest of Pinos Altos, on the western slope of the 
Pinos Altos Mountains (not shown on the map), Paleozoic limestones 
are intruded by diorite porphyry and in consequence replacement ore 
bodies were formed. The diorite porphyry forms the crest and much 
of the main mass of Pinos Altos Mountains. The granodiorite is 
found along the lower eastern slope and in the territory to the east. 


Tradiytie and 


Border fades 
of granodiorite 


Diorite, diorita 
, andeaiti 

ponplmy, a^eaitle 
Ofa ecfai » : *** 


Fifture vdna 


1. Little Key 

2. MoantataKigr 
& Ohio 

4 PteUlcL Astae, 

6w Tmpieo 

6L Langston 

7. Ariaona 

& Mina Grande. 
Kitpt Woman 

9l Oopoer 
10. Ifaounoth 
IL Deepdowaand 

H 1 2Uilea 

FiouRB 10.— Kap showing geologic relations of fissure valxis near Pinos Altos, N. Mex. Stippling Indi- 
cates relleL 



The granodiorite may be divided into two parts — (1) a very homo- 
geneous pure mass of pear-shaped outcrop, with Pinos Altos near its 
center, and (2) a more basic and less homogeneous phase of this mass 
at its southern and southeastern border. The boundaries between 
the homogeneous mass and its more basic phase and between the 

Digitized by 



pure mass and the diorite porphyiy may be drawn with considerable 
sharpness. On the other hand, the eastern and southern contact of 
the basic phase of the granodiorite with the diorite porphyry com- 
plex is not so easily to be placed on the map, for along the southern 
border especially offshooting dikes and fine-grained border f acies of 
the granodiorite form a ragged edge and obscure the relations. 

The pure granodiorite mass is a fairly coarse grained, holocrystal- 
line granitoid rock with a pinkish cast. Hornblende is the prominent 
ferromagnesian mineral. The rock varies somewhat in texture but 
within the area mapped as pure granodiorite is a remarkably homo- 
geneous unit. In the field it is unmistakable; it forms locally almost 
bare rocky knolls and cliffs, is well jointed, and weathers differently 
from the other rock of the vicinity, in large angular blocks whose 
dimensions are determined by the spacing of joint planes. Miner- 
alogically the rock is a holocrystalline coarse-grained aggregate of 
orthoclase, albite, andeaine, and andesine-labradorite feldspars with 
quartz and abundant colorless to light-green hornblende. Magnetite, 
apatite, titanite, and a little zircon are present, as is usual in such 
granitic rocks. The secondary minerals are chlorite, sericite, and 

Though the border f acies is in a broad way mineralogically similar 
to the main mass, it differs in being less homc^eneous; that is, 
within it are a number of related types presenting minor variations in 
composition and texture. The essential mineralogical differences are 
the development of pyroxene and biotite at the expense of horn- 
blende and a lower content of free quartz. A finer grain along the 
borders and a general lack of textural homogeneity are also evident. 
It is believed that fragments of the surrounding intruded diorite 
porphyry are present in this area. Some of the types mapped 
together are undoubtedly offshooting dikes from the main mass, v^ry 
similar to it in composition and texture, though locally finer grained 
and porphyritic; but the more striking variations in composition are 
probably a result of successive but related injections of differen- 
tiated magma. 

These pyroxene-biotite rocks, however, may also be classed as 
granodiorites. Two specimens within this area, one from the south- 
western and one from the northeastern border, show, when examined 
under a microscope in thin section, the striking pecuUarity that large 
anhedral orthoclase feldspar crystals are the hosts in which have 
crystallized numerous perfect laths of andesine-labradorite feldspar 
and pyroxene. Large pleochroic biotite plates likewise inclose 
plagioclase feldspar; a little interstitial quartz is present, also 
apatite. The whole is a beautiful example of poikilitic growth. 

At the extreme south end of the Pinos Altos Mountains, associated 
with the rock just described, are two phases of the pyroxene grano- 

Digitized by 



dbdte. One has a dttik-greoia aspac4, owing to the abundance of 
bbtita and pYiomme. The oilier ia ligktar in oobr and has a puddah 
caat on weaiJ^red aurfaees. 

Th* daiker phaae conaista easantiallj of aboadant pTroxeoe and 
biotito wiih intarioddng andoina-labradoiita fialdapar laths and 
aubsidiarj orthachae. The faiotita oeciin in huge pktes and mueh 
of it auROunda grains of pyroxane and tiibaaiCamis magnetite. 
Apatite ia abundant. Tlie orthodaae faldapaor hae a tandency to 
inebae the phgiodaee poikiUiticaUy — ^that ia, it ia ktar than the 

The mora addie phase ia a granitoid rock eonmating of abundant 
orthech«e (with aHhaidiary pJagiochiee) and hiotite withnumeHroas and 
rdetirdj ktfge pjMoiene prisms. Perfaapa it might better be called 
a pyroxene ayenite. 

It may be said with a conaiderable degree of asMirance that the 
graaodiiurite is of later age than the diorite porphyry eomplaz which 
sarrounde it. Evidense for tiiia conclnaioii eonskta mainly in the 
three facta that (1) oftheotii^ dikee, some exactly similar in compo- 
sition and texture to the main maaa and some presantii^ porphyritic 
phases, may be found in the surrounding complex; (2) there seems to 
be a distinct finaaaaa of grain developed locally near the oontact; 
and (3) th* incfeaaing battcity of the magma near the contact is a 
phaaomeaHi obaarved ia other regions at the hordar of intruave 

naoBm PonrHTBT ▲in> Aixinn xocxa. 

The group of rocks into which the granodiorite is intruded ia char- 
acterized by a dark-g;reen or steel-blue color and by a fine-grained 
porphyritic or nearly aphanitic texture. In the vicinity of Finos 
Altos much of the rock is diorite porpl^yry er fine^ained diorite. 
The area represented on the map is but a part of a widespread series of 
rocks which have been grouped together aa a tinit, by the writer, for 
convenienee in mj^pping the Silver City quadrapgjie. The series 
includes andesitic flow breccias, intrusive andesite porphyries, pyrox- 
ene andesite porphyries, dioritea, diorite porphyries, md allied roeks. 

Though and.eaite breccias may be seen in Finos Altes Mountain, the 
main portion ef that mass ia essentially fine-grained diorite and diorite 

It is this complex, then, generally dark ia color and fine graiiked in 
tesd^uie, which forms the country rock into which the granodiorite was 
intruded. The diorite consists essentially of andesine-lahradorite 
feldspar in interlocking stout prisms, a subordiuate but ZK)te- 
worthy amount of orthoclase, abundant well-developed crystals of 
pyroxene, much biotite in smaJl grains and laige plates, a little green 
hornblende, and numerous grains of iron oxide. 

Digitized by 



Tlie diorite porphyries hare essentiallj the same minerals. The 
groimdmaafi is either a fine granular mixture of orthoclase and plagio- 
claae or a mat of interlocking rodlike plagioolase crystals throughout 
which may be seen some ortluxdase. In some specimens hornblende 
is more abundant than in the diorite. Apatite needles are abundant 
in some specimens. Phenocrysts may consist either of plagioclase, 
oithodasey or pyroxene, or of all of them. Much alteration of pyrox- 
ene to hornblende is evident. Secondary cakite, chlorite, and seri- 
cite are plentiful in some specimens. 

The aadesitic rocks are Ught brown, olive-green, purple, or gray- 
blue in color. They have a glassy or partly glassy grotmdmass in 
which are set numerous short, stout andesine-feldspar and pyroxene 
phenocrysts. Chlorite and zeolites may be seen filling gas cavities. 
The andesitic flow breccias are, it is beUeved, the oldest of this group. 
Several generations of dikes are present. 


The lava flow which to the north covers both the granodiorite and 
the diorite porphyry is a part of a great series of flows of latitic, 
rhyolitic, and basaltic facies and interbedded tuffs with sediments. 
The area shown on the map is covered by lavender-colored lava flows 
of rhyolitic and latitic type. Some portions of this mass are fine 
grained and glassy, some medium grained and crystalline, others 
decidedly rough in appearance. They all consist essentially of clear 
oligoclase or sanadine feldspars, leached bronze-colored biotite, a very 
little quartz, and a glassy or partly glassy groundmass. 


GenercX relations. — ^The important fissure veins of the district trend 
from nearly north to northeast, most of them lying between N. 18® E. 
and N. 30** E., one nearly north and one N. bb"" E. They cut both 
diorite porphyry and granodiorite and cross the contact between these 
rocks. (See fig. 10, p. 110.) 

The dips are steep and incline both to the east and west. The 
veins may be traced various distances on the surface, from a few 
htmdred feet to nearly a mile. All of them die out on the surface 
in a horizontal direction by spliting up or fingering out into ramify- 
ing veinlets. The distance between the walls of the veins differs in 
different (deposits and also in individual deposits, from a few inches 
to 6 feet or more. Generally, though not invariably, the waUs are 

The only mine map available to the writer showed that at one 
place a vein split into two parts and came together again along the 

94174'*— Bun. 470—11 S 

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Mineralogy. — The veins as a group are characterized by a decided 
similarity in their mineral content. In all of them may be found 
quartz, iron pyrite, chalcopyrite, and calcite, and most of them 
contain in addition to these ndnerals rosin-colored, brown, and 
black sphalerite and galena. In some of them barite and rhodochro- 
site were noted. Gold and silver are present in all the veins. 

It is true, however, that though so similar in their mineral content 
these veins would, if opportunity were afforded to study them under- 
ground, reveal individual combinations and arrangements of their 
ores and gangue which might be characteristic. No such study 
couid be made. 

Origin of ike veins. — ^The veins are without doubt the result of 
open-fissure filling; tensional stresses were powerful enough to 
fractiu*e the rocks and to keep open the fractures formed; and ther<d 
is evidence in the veins that fractures closed by vein filling were 
reopened by renewed fracturing. 

The process of open-fissure filling is beautifully demonstrated in a 
specimen from the Pacific vein found on the dump at the Hearst 
shaft. (See fig. 11.) The specimen covers the entire width of the 
vein and its polished surface is therefore a perfect cross section. 
Five distinct bands proceeding from each wall inward to the center 
may be counted. Each of these bands has an almost perfect counter- 
part on the opposite side of the vein. The first band, that next to 
the wall, contains quartz and pyrite. Its inner edge is outlined by 
the crystalline terminations of quartz prisms, a beautiful example of 
comb structure. The succeeding band is composed of zinc sulphide 
(sphalerite) and chalcopyrite. The chalcopyrite grows more abundant 
toward the iimer edge and in fact forms two subsidiary bauds separ 
rated by a thin band of sphalerite. The next layer, a thin band, 
contains quartz and chalcopyrite. It is, followed by a narrow band 
of sphalerite, which is in tmn followed by a thicker baud of quartz 
that contains fine grains of disseminated chalcopyrite and locally 
fails to join with its corresponding band on the opposite side, leaving 
an open crystalline cavity at the center. 

On one wall of the vein is a secondary narrow vein, evidently a 
reopened fissure. Its walls are outlined by narrow bands of quartz 
(with a little chalcopyrite aud a little galena), between which is a 
pinkish cream-colored mass of ferriferous and magnesian carbonates 
and quartz. The narrow quartz bands forming the walls of this 
little vein have locally been broken, and pieces of the wall'^ow lie at 
varying angles across the vein embedded in the vein filling. 

On the opposite wall of the main vein a fragment of country rock 
is included in and surroimded by the vein material of the large vein. 
This fragment of country rock is interesting because of the earlier 
veining which it displays. First, it contains parallel hairlike frao* 

Digitized by 




tures filled with sphalerite and iron pyrite; second, crosscutting 
heavier fractures filled with sphalerite and iron pyrite; and third, dis- 
seminated pyrite apparently not related to any fractures. 

From these data tilie history of the mineralization of this particular 
vein may be deduced. A fracture was formed in the coimtry rock 
and filled by solutions carrying zinc and iron sulphides. Fracturing 



Swi ciliJ i d fm*- ONbomtM, mmrtz, 

FioxTRX 11.— Spedmen from Paciflo vein, showing evidanoe of open-flasaie fllllng. One-half natural siia. 

continued and cross fissures on a small scale were opened. The 
forces, of whose presence this initiatory fracturing was but a pre- 
liminary mark, finally succeeded in producmg an open fracture 
measured by the widti of the vein described, and solutions carrying 
silica and iron sulphide and a trace of zinc sulphide and lead circu- 

Digitized by 



lated through the opeu spaces thus afforded. Along both walls 
siinultaneoualy quartz and pyrite were prec^itated, and continued 
to be precipitated, apparenUj, imtil soIuUobb ceased to circulate or 
ceased to carry sulphur, iron, and silica, for the boundary between 
this first band and the succeeding one is sharp in point at both 
demarcation and mineral content. When next mineralizing waters 
flowed past the walls zinc sulphide and chalcopyrite were deposited, 
and it is evident from the specimen that, although copper, sulphur, 
and iron were present during the remaining history of the vein, 
though growing markedly less toward the end, the zinc sulphide 
and silica content fluctuated, first a layer of one and then a layer of 
the other being precipitated. Parts of the vein along the center 
were probably never completely filled, not because there was a lack 
of material, but because deposition fortuitously isolated open geode- 

like spaces within which 
circulation ceased. 

The small vein at the 
edge of the large one 
points to a continuation 
of fracturing in the re- 
gion and the advent of 
carbonated waters marks 
a distinct change in the 
mineralizing solutions. 
So far as this specimen is 

FiouBE 12.-Cro9S aectlsB showing oomb rtnictare to a rniall COncemcd, thcSC Carbon- 
vein. Black areas in4ioat« qwrtt; white areai, caldte; ihaded atcd WatcrS, Canying also 
area., ferrife«H» earbonate.. ^jjj^^^ ^j^^^ ^^ ^^^ ^^ 

mineralization. Worthy of note is the relatively late and sudden 
introduction of the copper-iron sulphide (chalcopyrite), also repeated 
alternations between sphalerite and quartz. 

Figure 12 represents a cross section of a smaller vein but illus- 
trates beautifully the comblike structure of the quartz lining each 
wall. The central portion of this small vein contains carbonates and 
a very few crystals of chalcopyrite. The undisturbed crystaUization 
of the inner ends of the quarts prisms leaves no doubt of the open 
character of the fissure. 

Details of veins. — In the accompanying table is summarized such 
information as was gathered in mapping the veins and studying 
the dumps and any additional facts regarding the mines that were 
reported to the writer. Eleven veins are represented on the map 
(fig. 10). They include all but one of the extensively developed 
veins of the district. The Silver Cell is not shown, nor a small vein 
known as the Alaska vein on the east border of Pinos Altos, nor could 

Digitized by 



Other slightly developed veins in the territory northeast of the 
Ileaist shi^t be mapped. 

A word of explanation is necessary regarding the interrelation of 
the Aztec, Pacific^ and Langston veins. From the south the Pacific 
and Langston veins approach each other and meet on the surface 
about 50 feet south of the Thayer shaft. The Aztec vein, therefore, 
becomes the northward extension of this pair, provided they do not 
cross each other. If they cross, then the Aztec may properly be 
considered the northward extension of the Langston. A map of that 
portion of the Pacific mine between the Hearst shaft and the Aztec 
tunnel does not show any crossing of two veins, nor was any such 
crossing seen on the surface. It is true that some distance northeast 
of the Aztec shaft in the territory east of the Aztec vein there occurs 
a vein, as yet but little developed, which might represent the north- 
east extension of the Pacific. But that this vmn could be traced 
continuously southward to a juncture with the Pacific vein at or 
near the Hearst shaft has not been proved. This vein corresponds 
somewhat closely in strike and dip with the Pacific vein, and the ore 
is reported by Mr. W. C. Chandler to resemble closely the ore of the 
Pacific vein. However, as there is no determinate evidence to the 
contrary, the Langston vein must for the present be considered a 
split-off from the Aztec-Pacific vein. 

In the Mountain Key mine during the time of its original operation 
ore was lost in the main shaft between the 600-foot and 700-foot 
levels. It is reported that since that time a crosscut into the hanging 
wall on the 700-foot level again struck the vein, and a drift was 
driven northeast 175 feet and southwest 200 feet. The last 600 tons 
taken from the mine and referred to in the table came from this drift. 

On what are known as the Monarch and Ontario claims, in the 
territory east and northeast of the northeast extension of the Aztec 
vein, is a vein which strikes N. 25® E. and dips 57® W. This vein 
throughout these two claims has been worked with arrastres down to 
a depth of 15 to 20 feet, and rich values are reported. Unaltered 
sulphides are said to have been struck at a depth of 40 feet. 

Digitized by 






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Geologic relations. — Carboniferous limestone forms a part of the 
west flank of the Finos Altos Mountains. The area of limestone is 
not large; a rectangular mass about 1^ miles long in a north-south 
direction and less than a mile in width is exposed. The strata dip 
eastward; into the mountain, and are unconformably overlain by 
basal Cretaceous quartzite beds. A few feet of limy shale overhe the 

The Paleozoic limestones are cut oflf on the west by a normal fault 
which drops Cretaceous shales and portions of the igneous complex 
against them. On the north, south, and east the limestone is boimded 
by intrusive igneous rocks of the andesite-diorite group. 

A normal fault; with the western block downthrown, passes in a 
northeasterly direction through the center of the area. A sedi- 
mentary block, therefore, broken by and partly limited by faults, lies 
practically surrounded by intrusive rocks. 

Figure 13 is an ideal section of the structure near the Cleveland group 
of claims. Limestones capped by quartzite dip southeastward, into 

FlGtrBB 13.— Ideal structare section near Cleveland groap of claims, a, Basal Cretaoeons qoartitte; 
b, Carboniferous limestone; c, dioilte and andeslte dikes; d, diorite porphyry and allied rocks. 

the mountain, and are intruded by the igneous complex which makes 
up the moxmtain. A fault followed by a dike drops the quartzite 
beds and limestone to arelatively low level westof the fault, and igneous 
rocks cut off the limestones on the west. 

Sulphide ores carrying ferriferous sphalerite, pyrite, and chalcopy- 
rite occur as replacements of the limestone. Veins are also present 
but were not examined by the writer. An excellent opportunity to 
examine the ore bodies of the replacement type was afforded in a 
development tunnel on the Cleveland group of claims, the property 
of George H. Utter, of Silver City. Bodies of the same type are 
also present on claims of C. Amory Stevens, which join the Utter 
property on the west. 

The ore is an intimate intergrowth of sphalerite, chalcopyrite, 
pyrite, quartz, and ferriferous carbonate. The relative proportion 
of these constituents may vary considerably, but the ore is usually 
this mixture. The sphalerite is well crystallized andlocally is arranged 
in roughly linear fashion, the elongated structure of the crystal giving 
the appearance of banding. Broken transversely to this banding the 


zed by Google 



mass appears as an irregular mixture of the component minerals. 
(See fig. 14.) 

The sphalerite is apparently crystallized in chains of tetrahedrons. 
An examination of it with a hand lens shows that very finely crystal- 
lized iron and copper sulphides are intergrown with it. Fine crushing 
would be necessary to make a clean separation. 

The main tunnel is 815 feet long and is driven into the hill; the 
deposits are further prospected by about 1 ,000 feet of drifts. In addi- 
tion there are many surface cuts. 

An examination of the tunnel and drifts suggests that the ore has 
replaced definite beds of the limestone in a fairly regular manner. 
The impression is gained that two distinct ore layers are present, 
separated by 4 to 15 feet of the limestone. The lower layer is about 
12 feet thick; the upper 25 feet or more. These layers are cut by 
basic dikes and displaced by faults. 
Figure 15 shows a profile along the 
main tunnel. It will be seen that 
the ore layers change their dip 
from easterly to westerly near the 
middle of the tunnel, and also that 
they are cut off apparently by a 
fault. A drill hole in the floor of 
the tunnel, 620 feet in from the 
face, struck ore and it is possible 
that the missing layers are beneath 
the floor. Using the data sup- 
pUed by Mr. Utter on the map of 
the tunnels and drifts, the writer 
has constructed a stereogram (fig. 
16) to represent pictorially the 

character of the ore layers, on thCp,^^ u-Sketch showing linear arrangement ol 
assumption that they retain the sphalerite in the Cleveland ore. t. Sphalerite; 

thickness and attitude suggested ^*^^^ 

by the mine workings. The stereogram is more regular than the ore 
body can possibly be but serves to suggest its nature and shape. 
The extension of the ore body to the north and south of the tunnel 
can be proved only by more developments, for replacement deposits 
in limestone are as a rule extremely irregular. The work already 
done, however, has revealed a considerable body of ore. 

On the surface extensive gossans are forms composed of a mixture 
of limonite, zinc carbonate, azurite, and earthy material, with a 
dark-brown material containing manganese, copper, and iron. 
Some of the zinc carbonate undoubtedly may be considered ore. It 
is important to note that a nimiber of these gossans outcrop to the 
north at an elevation above the sulphide bodies developed imder- 

Digitized by 



ground and may represent the protruding edges of higher replaced 
ore-bearing beds. 

The following assays are rep<»ted to be oomposite assayB rapre- 
senting three separate samplings, including that of new era exposures 
in the fall and winter of 1909-10. The giround sampled is, for con- 
venience, divided into five blocks. (See plan, fig. 15.) 

FiQUBB 15.— Plan and approximate profile of Cleveland toimel, showing dikes and location of ore block, 
a. Dikes; b, ore; 1, (^foot winse in ore; 2, 40-foot upoalBe, gomaik and cariMoata; S, 3Moal ikalt la eu- 
bonates; 4, 10-foot npralae to upper ore body; 5, 47<loot upraise, a lover i:MDot layer of ore e^ p a n U gd 
from an upper 16-foot layer of ore by 12 feet of limestone; 6, 30-foot upraise, ore at top; 7, 22Hoot upraise; 
8, 15-lbot upraise, ore probably £ or 10 feet higher; 9, l84K>t vpnise, 20+ feei of oraf 10, flMbetupniaQ, 
18 feet of ore; 11, 2&-foot upraise, no ore; 12, 20-foot upraia^ no on; IZ, ao-toot ivnalset no on* dcill hole 
to ore 7 feet below raise. 

Assays of ore from Cleveland group. 




Block 1 




Block 2 



Block 4 

Ml 60 



Tlie samples from which the above assays were computed are 
reported to include a large number taken from a mixed material 
adjoining the ore bodies and containing small values, thus reducing 
the averages. This material will not have to be mined. 

In addition to these metals, gold is reported ranging from 20 cents 
to $1 a ton. The iron and copper pyrite when separated from the 
sphalerite is reported to average S3 in gold. A car of ore coiiitaining 
an excess of silica and a quantity of wall lime rock was shipped to 
Denver to be sampled and worked by the Huff process. Tlie ore 
assayed gold 0.02 ounce, silver 2.80 oimces, copper 1.15 per cent. 


zed by Google 


zinc 15.32 per cent, iron 22.60 per cent, silica 27.14 per cent, lime 
5.60 per cent, and sulphur 23.30 per cent. 

The Stevens property, which adjoins the develand group on the 
west, has many of the characteristics of the deposits just described. 
From the developments in a tunnd on the property, however, the 
impression was gained that the limestone was more irregularly 
replaced, perhaps without definite relation to bedding planes. Silver 
v^ues are reported to be considerably higher on this property and 
galena is an important part of the ore mixture. 

Origin of ffie ores. — The ores occurring as beds or irregular masses 
in the limAstones are probably related genetically to the basic rocks 
which have intruded tiiese limestones. The question might be raised 
whether the small dikes or the large intrusive mass caused the mineral- 
ization. The little evidence that was observed to aid in such a decision 
is conflicting. As against the introduction of ore by the smaller 

'*'•'*''*' *'•*' 

DBbBs Orervpilacta^ 


FiouBS 16w— Steraogiaai sbowtaig ehamctsr of ore layen la Clevelattd miiM. On block No. 2 bekmgs at 
point marked **a," but Is not shown. 

dikes it could be said that in the Cleveland tunnel the dikes cut the 
ore bodies and the ore planes so far as developed continue on their 
strike and dip irrespective of the dikes. On the other hand, near the 
face of the develand tunnel, a small patch of ore lies directly against 
a dike, suggesting a local origin, but this patch was not completely 
exposed and may have entered from the roof. Against the small 
dikes IS also the fact that some of the dikes cut the limestone with no 
apparent contact effect on it. Therefore, though it is admitted 
that the intrusion of the main mass and that of the smaller dikes were 
probably very close in point of time, it is believed that the major 
effects of mineralization were produced by the larger body. It is a 
fair assumption on this hypothesis that more ore wSi be found as the 
main igneous mass to the east is approached, and also that other ore 
layers or bodies may be encountered below as well as above the 
exposed layers. 

Digitized by 



The following list includes the more important publications by the 
United States Geological Survey, exclusive of those on Alaska, on 
precious metals and mining districts. Certain mining camps, while 
principally copper or lead producers, yield also smaller amounts of 
gold and silver. Publications on such districts are listed in the 
bibUographies for copper and for lead and zinc. When two metals 
are of importance in a particular district, references may be dupli- 

These publications, except those to which a price is aflSxed, may 
be obtained free by applying to the Director, United States Geolog- 
ical Survey, Washington, D. C. The priced publications may be 
purchased from the Superintendent of Docimients, Government 
Printing Office, Washington, D. C; the monographs from either the 
Director of the Survey or the Superintendent of Documents. 

Abnold, Ralph. Grold placers of the coast of Washington. In Bulletin 2G0, 
pp. 154-157. 1905. 40c. 

Bais, H. F. Reported gold deposits of the Wichita Mountains [Okla.]. In Bulle- 
tin 225, pp. 120-122. 1904. 35c. 

Ball, S. H. €reological reconnaisBance in southwestern Nevada and eastern 
California. In Bulletin 285, pp. 5&-73. 1906. 60c. Also Bulletin 308. 218 pp. 

Bakcropt, Howland. Reconnaissance of the ore deposits in northern Yuma 
County, Ariz. Bulletin 451. 130 pp. 1911. 

Barbell, Joseph. Geology of ^e Marysville mining district, Montana. Profes- 
sional Paper 57. 178 pp. 1907. 

Becker, G. F. Geology of the Comstock lode and the Washoe district; with atlas. 
Monograph III. 422 pp. 1882. $11. 

Gold fields of the southern Appalachians. In Sixteenth Ann. Rept., pt. 

3, pp. 251-331. 1895. 

Wltwatersrand banket, with notes on other gold-bearing pudding stones. 

In Eighteenth Ann. Rept., pt. 5, pp. 153-184. 1897. 

Brief memorandum on the geology of the Philippine Islands. In Twen- 
tieth Ann. Rept., pt. 2, pp. 3-7. 1900. 

Boutwbll, J. M. Economic geology of the Bingham mining district, Utah. Pro- 
fessional Paper 38, pp. 73-385. 1905. 

Progress report on Park City mining district, Utah. In Bulletins 213, pp. 

31-40 (25c.); 225, pp. 141-150 (35c.); 260, pp. 150-153 (40c.). 

Calkins, F. C, and MacDonald, D. F. A geologic reconnaissance in northern 
Idaho and northwestern Montana. Bulletin 384. 112 pp. 1909. 

Collier, A.J. Gold-bearing river sands of northeastern Washington. In BulIetiD 
315, pp. 56-70. 1907. 

Cross, WnrrMAN. General geology of the Cripple Creek district, Colorado. In 
Sixteenth Ann. Rept., pt. 2, pp. 13-109. 1895. $1.25. 

Digitized by 



0&O88, Wbitman. Geology of Silver Cliff and the Rosita Hills, Colorado. In 
Seventeenth Ann. Rept., pt. 2, pp. 269-403. 1896. 

Cboss, Whitman, and Spencer, A. C. Geology of the Rico Mountains, Colorado. 
In Twenty-first Ann. Rept., pt. 2, pp. 15-165. 1900. 

Ctjbtis, J. S. Silver-lead deposits of Eureka, Nev. Monograph VII. 200 pp. 
1884. $1.20. 

DzLLEB, J. S. The Bohemia mining region of western Oregon, with notes on the 
Blue River mining region. In Twentieth Ann. Rept., pt. 3, pp. 7-36. 1900. $1.50. 

Mineral resources of the Indian Valley region, California. In Bulletin 260. 

pp. 45-49. 1905. 40c. 

Geology of the Taylorsville region, California. Bulletin 353. 128 pp. 


BxLLER, J.'S., and Kay, G. F. Mines of the Riddles quadrangle, Oregon. In 
BuUetin 340, pp. 134-151. 1908. 

Mineral resources of the Gnmts Faaa quadrangle and bordering districts, 

Oregon. In Bulletin 380, pp. 48-79. 1909. 

Eckel, £. 0. Gold and pyrite deposits of the Dahlonega district, (Georgia. In 
BuUetin 213, pp. 57-63. 1903. 25c. 

Emmons, S. F. Geology and mining industry of Leadville, Colo.; with atlas. 
Monograph XII. 870 pp. 1886. $8.40. 

Progress of the precious-metal industry in the United States since 1880. 

In Mineral Resources TJ. S. for 1891, pp. 4&-94. 1892. 50c. 

Economic geology of the Mercur mining district, Utah. In Sixteenth 

Ann. Rept., pt. 2, pp. 349-369. 1895. $1.25. 

The mines of Custer County, Colo. In Seventeenth Ann. Rept., pt. 2, 

pp. 411-472. 1896. $2.35. 

Emmons, S. F., and Ibvino, J. D. Downtown district of Leadville, Colo. Bulle- 
tin 320. 72 pp. 1907. 

Emmons, W. H. The Neglected mine and near-by properties, Colorado. In 
Bulletin 260, pp. 121-127. 1905. 40c. 

Ore deposit^ of Bear Creek, near Silverton, Colo. In Bulletin 285, pp. 

25-27. 1906. 60c. 

The Granite-Bimetallic and Cable mines, Philipsburg quadrangle, Mon- 
tana. In Bulletin 315, pp. 31-65. 1907. 

Gold deposits of the Little Rocky Mountains, Montana. In Bulletin 340, 

pp. 96-116. 1908. 

Reconnaissance of some mining camps in Elko, Lander, and Eureka coun* 

ties, Nev. Bulletin 406. 126 pp. 1910. 

Emmons, W. H., and Gabrey, G. H. Notes on the Manhattan district, Nevada. 
In Bulletm 303, pp. 84^93. 1907. 
Gale, H. S. The Hahns Peak gold field. In Bulletin 285, pp. 28-34. 1906. 60c. 

Gold placer deposits near Lay, Routt County, Colo. In Bulletin 340, pp. 

84-95. 1906. 

Graton, L. C. Reconnaissance of some gold and tin deposits of the southern 
Appalachians; with notes on the Dahlonega mines, by Waldemar Lindgren. Bulletin 
293. 134 pp. 1906. 

Hague, Arnold. Creology of the Eiueka district, Nevada. Monograph XX. 
419 pp. 1892. $5.25. 

Hahn, O. H. The smelting of azgentiferous lead ores in the Far West. In Mineral 
Resources U. S. for 1882, pp. 324-345. 1883. 50c. 

Hess, F. L. Gold mining in the Randsburg quadrangle, California. In Bulletin 
430, pp. 23-47. 1910. 

Hill, J. M. Notes on the economic geology of southeastern Gunnison County, 
Colo. In Bulletin 380, pp. 21-40. 1909. 




Hill, J. M. Notes on the placer depoeitB of Qrealerville, Ariz. In BuUcrtan 430, 
pp. 11-22. 1910. 

iBYiHa, J. D. Ore depodtB at the northern Black Hills. In Bulletia 225, pp. 
12S-140. 1904. 35c. 

^ Ore deposits of the Oniay district, Colorado. In Bulletin 260, pp. 50-77. 

1905. 40c. 

Ore deposits in the vicinity of Lake City, Colo. In Bulletin 200, pp. 

78^84. 1905. 4Idc. 

iRvnco, J. D., and Emhons, 8. F. Economic resources of northern Black Hills. 
Professional Paper 26, pp. 53-212. 1904. 

LiNDOBBN, Waldbhab. The gold-silver mines ol Of^ir, Gal. In Fourteenth Ann. 
Rept., pt. 2, pp. 24S-284. 1894. $2.10. 

The gold-quartz veins of the Nevada City and Giass Valley districts, Cali- 
fornia. In Seventeenth Ann. Kept., pt. 2, pp. 1-262. 1896. $2.35. 

The mining distrtcts of the Idaho Basin and the Boise Ridge, Idaho. In 

Eighteenth Ann. Kept., pt. 3, pp. 625-736. 1896. $2.15. 

The gold and silver veins of Silver City, De Lamar, and other mining dis- 
tricts in Idaho. In Twentieth Ann. Rept., pt. 3, pp. 75-256. 1900. $1.50. 

The gold belt ci the Blue Mountains of Oregon. In Twenty-eecond Ann. 

Rept., pt. 2, pp. 551-776. 1902. 

Mineral deposits of the Bitterroot Raage and the Clearwater Mountains, 

Montana. In Bulletin 213, pp. 66-70. 1903. 25c. 

Tests for gold and silver in shales from western Kansas. Bulletin 202. 

21pp. 1902. 5c. 

The production of g(4d in the United States in 1904. In Bulletin 260, pp. 

32-38. 1905. 40c. 

The production of silver in the United States in 1904. In Bulletin 260, pp. 

39-44. 1905. 40c. 

The Annie Laurie mine, Piute County, Utah. In Bulletin 285, pp. 87-90. 

1906. 60c. 

Notes on the Dahlonega mines. In Bulletin 293, pp. 119-128. 1906. 

Geology and gold deposits of the Cripple Creek district, Colorado. Pro- 
fessional Paper 54. 516 pp. 1906. 

A geological analysis of the silver production of tke United States in 1906. 

In Bulletin 340, pp. 23-35. 1908. 

Resources of the United States in gold, silver, copper, lead, and zinc. In 

Bulletin 394, pp. 114-156. 1909. 

LiKDGBEN, Waldemab, and Graton, L. 0. Mineral deposits ol New Mexico. In 
BuUetin 285, pp. 74-86. 190e. 60c. 

Lindoben, Waldemab, Gbaton, L. C, and GoBnoir, C. H. The ore deposits of 
New Mexico. Professional Paper 68. 361 pp. 1910. 

Liin>OBBN, Waldemab, and McCaskbt, H. D. Gold and silver. In Mineral 
Resources U. S. for 1909, pt. 1, pp. 121-150. 1911.» 

LiNDGBEN , Waldbmab, and Raksohb , F. L. The geological resurvey of the Cripple 
Creek district. Bulletin 254. 36 pp. 1905. 

Lobd, EuoT. Comstock mining and miners. Monograph IV. 451pp. 1883. $1.50. 

MaoDonald, D. F. Economic features of northern Idaho and northeastern Mon- 
tana. In Bulletin 285, pp. 41-52. 1906. 60c. 

Notes on the Bohefliia mining district, Oregon. In Bulletin 380, pp. 

80-84. 1909. 

The Weaverville-Trinity Center gold gravels. Trinity County, Oal. In 

Bulletin 430, pp. 48-58. 1910. 

1 See also Gold, sUver, oopper, lead, and cino (mine production) in Western, Central, and Eastern 
States, by several authors. In Mineral Resouroes U. 8. for 1900, pt. 1, pp. 217-^48, 1911. 

Digitized by 



McCabkbt, H. D. Notes on some gold depofiite of Alabama. In Bulletin 340, 
pp. 36-52. 1908. 

NiTZB, H. B. C. History of gold mining and metallurgy in the Southern States. 
In Twentieth Ann. Kept., pt. 6, pp. 111-123. 1899. 

Pabdbb, J. T. Faulting and vein structure in the Cracker Creek gold district, 
Baker County, Oreg. In Bulletin 380, pp. 85-93. 1909. 

Placer gravels of the Sumpter and Granite districts, eastern Oregon. In 

BuUetin 430, pp. 59-65. 1910. 

Pbnbosb, R. a. F., Jr. Mining geology of the Cripple Creek district, Colorado. 
In Sixteenth Ann. Rept., pt. 2, pp. 111-209. 1895. $1.25. 

PuBiNGTON, C. W. Preliminary report on the mining industries of the Telluride 
quadrangle, Colorado. In Eighteenth Ann. Rept., pt. 3, pp. 745-850. 1898. $2.15. 

Ransoms, F. L. Report on the economic geology of the Silverton quadrangle, 
Colorado. BuUetin 182. 265 pp. 1901. 50c. 

The ore deposits of the Rico Mountains, Colorado. In Twenty-second Ann. 

Rept., pt. 2, pp. 229-398. 1902. 

Preliminary account of Goldfield, Bullfrog, and other mining districts in 

southern Nevada. In Bulletin 303, pp. 7-83. 1907. 

Geology and ore deposits of Goldfield, Nev. Professional Paper 66. 258 

pp. 1909. 

Some mining districts of Humboldt County, Nev. Bulletin 414. 75 pp. 


The Homsilver district, Nevada. In Bulletin 380, pp. 41-43. 1909. 

Round Mountain, Nevada. In Bulletin 380, pp. 44-47. 1909. • 

Ransoms, F. L., and Calkins, F. C. Geology and ore deposits of the Coeur d' Alene 

district, Idaho. Professional Paper 62. 203 pp. 1908. 85c. 

Ransoms, F. L., Emmons, W. H., and Garbet, G. H. Geology and ore deposits 
of the Bullfrog district, Nevada. Bulletin 407. 128 pp. 1910. 

SoHSADSB, F. C. Mineral deposits of the Cerbat Range, Black Mountains, and 
Grand Wash ClifEs, Mohave County, Ariz. In Bulletin 340, pp. 53-84. 1908. 

The mineral deposits of the Cerbat Range, Black Mountains, and Grand 

Wash ClifEs, Mohave County, Ariz. Bulletin 397. 226 pp. 1909. 

ScHULTZ, A. R. Gold developments in central Uinta County, Wyo., and at other 
points on Snake River. In Bulletin 315, pp. 71-88. 1907. 

SsvsBAL AI7THOB8. Gold, silver, copper, lead, and zinc (mine production) in 1909 
in Western, Central, and Eastern States. In Mineral Resources U. S. for 1909, pt. 1, 
pp. . 1911. 

Smith, G. O. Gold mining in central Washington. In Bulletin 213, pp. 
76-80. 1903. 25c. 

Quartz veins in Maine and Vermont. In Bulletin 225, pp. 81-88. 1904. 


Spubb, J. E. Economic geology of the Mercur mining district, Utah. In Six- 
teenth Ann. Rept., pt. 2, pp. 343-455. 1895. $1.25. 

Creology of the Aspen mining district, Colorado; with atlas. Monograph 

XXXI. 260 pp. 1898. 13.60. 

The ore deposits of Monte Cristo, Washington. In Twenty-second Ann. 

Rept., pt. 2, pp. 777-866. 1902. 

Ore deposits of Tonopah and neighboring districts, Nevada. In Bulletin 

213, pp. 81-87. 1903. 25c. 

Preliminary report on the ore deposits of Tonopah. In Bulletin 225, 

pp.8»-110. 1904. 35c. 

Ore deposits of the Silver Creek qiuidrangle, Nevada. In Bulletin 225, 

pp. 111-117. 1904. 35c. 

94174*— Bull. 470—11 

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Spubb, J. £. Notes on the geology of the Goldfield difltiicC, Nevada. In Bulletin 
225, pp. 118-129. 1904. 35c. 

Geology of the Tonqpah mining district, Nevada. Fh>fe8S]onal F^per 

42. 295 pp. 1905. 

The oces of Qoldfield, Nev. In Bulletin 260, pp. 132-139. 1905. 40c. 

Development of Tonopah during 1904. In Bulletin 260, pp. 140-149* 

1905. 40c. 

Ore depoedts of the Silver Peak quadrangle, Nevada. Profeaaional Fbper 

56. 174 pp. 1906. 

Spubr, J. £., and Gabr^t, G. H. Preliminary report on the ore depositB of the 
Geoigetown mining district, Colorado. In Bulletin 260, pp. 99-120. 1905. 40c. 

The Idaho Springs mining district, Coloiado. In Bulletin 285, pp. 35-40. 

1006. 60c. 

Economic geology of the Geocgetown quadrangle (together with the Empire 

district), Golofado, wiUi geneial geology by S. H. Bail. IWesHJonal Paper 63. 422 
pp. 1908. 

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district, Utah. In Nineteenth Ann. Rept., pt. 3, pp. 601-767. 1899. $2.25. 

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mineral deposits of the Neihart, Barker, Yogo, and other districts. In Twentieth 
Ann. Rept., pt. 8, pp. 271-461. 1900. |1.50. 

Gold mines of the Marysville district, Montana. In Bulletin 213, pp. 

88-89. 1903. 26c. 

» Notes on the gold veins near Great Falls, Md. In Bulletin 260, pp. 

128-131. 1905. 40c. 

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mining district, Jefieison County, Mont. In Twenty-second Ann. Rept., pt. 2, pp. 
399-550. 1902. 

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trict, Montana. Bulletin 139. 164 pp. 1896. 15c. 

Geology and mining resources of the Judith Mountains of Montana. In 

Eighteenth Ann. R^t.,pt. 3, pp. 44^-616. 1898. $2.15. 

Wbbks, F. B. Geology and minezal resources of the Osceola mining district, White 
Pine County, Nev. In Bulletin 340, pp. 117-133. 1908. 

WnxiAica, AiiBXBT, jjl Popular fallacies regarding precious-metal ore deposits. In 
Fourth Ann. Rept., pp. 253-271. 1884. $1.65. 

WooLSBY, L. H. Lake Fork extension of the Silverton mining area, Colorado. 
In BuUetin 315, pp. 26-30. 1907. 

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By Sidney Paige, 


The Burro Mountains lie near and southwest of Silver City, Grant 
County, N. Mex. Silver City is reached by a spur of the Atchison, 
Topeka & Santa Fe Railway, which connects with the main line at 
Deming, N. Mex., a town about 46 miles to the south. The Southern 
Pacific Railroad likewise passes through Deming. 


The Burro Mountains consist of two distinct mountain masses, the 
Big Burros and the Little Burros (see map, PI. IV) , rising near the 
border of a semidesert region. For many miles to the south stretches 
a waste of sand and gravel, whose unwatered expanse is broken only 
by precipitous, isolated mountain masses. Near Silver City this 
desai; region merges with the mountain country, and the flat, sandy, 
featureless plain rises gently to meet the hills. Here infrequent but 
torrential rains have cut numerous gullies, separated by flat-topped 
divides, the whole an intricately carved, sloping, gravd plain. 

The Little Burro Mountains rise out of this dissected expanse of 
semiconsolidated gravel about 6 miles southwest of Silver City. Far- 
ther to the southwest, about 15 miles from Silver City, is the conical 
mass of the Big Burros. 

The Little Burro Mountains trend northwest and southeast, are 
about 8 miles long and half a mile to IJ miles wide, and rise to an 
elevation of about 6,500 feet above the sea, or about 500 to TOO 
feet above the general level of the surrounding area. The western 
face of these mountains is generally steep, locally precipitous, and 
rises abruptly from the dissected gravel plain. The east side, on 
the other hand, merges gradually with this plain. 

The Big Burro Mountain mass is subconical in form, and its flanks 
slope from a central peak, at an elevation of 8,054 feet, at first steeply 
and then gently, to meet and finally merge with the desert deposits 
at its base. 


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The Continental Divide passes in a northeast-souUiwest direction 
through this region. The summit of the Big Burros is a point on 
this line, as also is the south end of the Little Burros. All drainage 
in this region north of this line is tributary to Gila River and thence 
by way of Colorado River to the Gulf of Colorado. All drainage 
south of the divide is lost in the sands of the desert. Mangas River, 
a tributary of the Gila, heading on the divide between the Little and 
Big Burros, receives much of the drainage of this region, and <«i the 
south Walnut, Cherry, and Oak Grove creeks are the more impK)rtant 
streams which carry the floods to the desert. None of these streams 
flow except after heavy downpours, when their beds become the paths 
of muddy torrents, which disappear as rapidly as they rise shortly 
after the cessation of rainfall. 


The Little Burro Mountains afford an excellent example of an ex- 
ceedingly fragmental geologic record. A study of the geology of the 
Silver City quadrangle ^ has supplied in large part the missing pages 
of its history. In this paper simply the principal facts will be stated 
and their discussion will be left for the later report. 

The rocks present in the Little Burro Mountains, named in the 
order of their age, are as follows: (1) Basal, pre-Cambrian granite; 
(2) Cretaceous quartzite with overlying Cretaceous shaly and limy 
beds; (3) a complex of andesitic breccias and intrusive rocks, which 
in part flowed out (probably) upon the Cretaceous land and in part 
intruded the Cretaceous rocks; (4) Tertiary (?) accumulations of 
gravels, sands, and tuffs, accompanied by widespread successive rhyo- 
litic and latitic and andesitic or basaltic lava flows; (5) intrusive 
stocks of rhyolitic or trachytic type; (6) Pleistocene and Recent 

The Cretaceous sediments and the Tertiary gravels, sands, and tuffs 
and accompanying lavas may be considered as bedded rocks — 
that is, rocks which originally formed horizontal or relatively hori- 
zontal deposits. These rocks now all dip at a considerable angle 
toward the east. The Little Burro Mountain mass, in other words, 
is a tilted fault block, elevated on its west side by a strong northwest- 
southeast fault. In addition to this main fault, transverse faults 
trending northeast and southwest break the main block into smaller 
units, and these, combined with intrusive volcanic stocks, have dis- 
turbed what little regularity the succession may have originally had. 
The map (PI. IV) wiU make clearer these rather complicated relations. 

^ Paige, Sidney, Sliver City folio, Geol. Atlas U. S., U. S. Geol. Sarrey (In preparaUon). 

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The west-oentral part of the mountains is made up of pre-Cambrian 
granite, upon whidi lie the basal quartzitic beds of the Cretaceous 
rocks. The remarkably even surface of the granite upon which the 
quartzites were deposited is of considerable significance as indicating 
the thoroughness with which erosion acted when planing off these 
rocks. Moreover, the presence of Cretaceous rocks resting upon a 
pre-Cambrian basement, when it is known that a few miles to the east 
hundreds of feet of sediment lie between the pre-Cambrian rocks and 
the CretAceous quartzites, indicates without question the long period 
of erosion preceding the deposition of the Cretaceous sediments. 

It is probable that after the deposition of the Cretaceous quartz- 
ites and the succeeding limy shales, another erosion interval pre- 
ceded the next stage in the geologic history of this immediate vi- 
cinity. This stage consisted in the intrusion of dark-colored ande- 
sitic material into the Cretaceous and older rocks and probably also 
the extrusions of lavas which flowed out upon the surface, for such 
igneous rocks overlie and cut the Cretaceous shales. Once more ero- 
sion probably had opportunity to alter the surface of the land, for the 
younger rocks of the region, rhyolitic and latitic, and basaltic lavas, 
with interbedded sediments and tuffs, lie as a blanket alike upon pre- 
Cambrian granite. Cretaceous sediments, andesitic breccias, and in- 
trusive rocks. 

This last outburst of volcanic material was followed by a period 
of faulting, perhaps post-Pleistocene, which resulted in the fracture 
of the mountains, and after these movements undoubted post-Pleisto- 
eene faults uplifted the western edge of the mountains. In connec- 
tion with these fault movements rocks of volcanic types were 


The geology of the Big Burro Mountains is far simpler than that 
of the Little Burros. The basal pre-Cambrian granite has been 
intruded by a quartz monzonite mass of subcircular outcrop, prob- 
ably of post-Cretaceous age. Rhyolitic dikes and stocks penetrated 
later the pre-Cambrian complex and perhaps intruded also the 
quartz monzonite, though evidence of this relation is not conclusive. 
The quartz monzonite is intruded, however, by aphanitic, rather 
acidic dikes, and also by dikes of quartz monzonite porphyry, iden- 
tical in mineralogical composition with the parent mass. 



The ore deposits about to be described may be placed in three 
classes: (1) Quartz veins; (2) irregular sulphide-impregnated frac- 

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ture systems, or shear zones in the pre-Cambrian complex; and (3) 
secondarily enriched deposits of disseminated cupriferous pyrite in 
the quartz monzcmite. Class 3 has many of the characteristics of 
class 2, but differs in that it is dominantly associated with the quartz 
monzonite, and in that the deposits are far more extensive than those 
of the other class. 



Well-defined quartz fissure veins traverse the pre-Cambrian gran- 
ite of the Little Burro Mountains, about If miles north of Tyrone 
post ofEce. (See PL IV, p. 132.) The veins examined by the writer 

are included in a group of 
12 claims controlled by the 
Woodward Mining Co. The 
map (fig. 17) shows four veins 
which have a northerly or 
northeasterly trend. The east- 
ernmost is known as the Con- 
tact vein; the next is the 
Wyman vein; the Casino is 
the next ; and the westernmost 
vein is not named to the 
knowledge of the writer. 

In general, it may be said 
that all these quartz veins fol- 
low fairly well defined fissures 
in pre-Cambrian granite. The 
Contact vein, for much of the 
distance over which it can be 
traced, follows a well-defined 
fault plane. The Casino fis- 
sure, too, shows some evidence 
of such an origin. It is not 
known that the walls of ihe 
two remaining veins have suf- 
fered any relative movement. 
The Contact vein, at present being developed near its south end by 
an incline, which at the time of the writer's visit was 170 feet deep, 
is opened by several other cuts and shallow shafts. From this incline, 
called the Virtue shaft, the vein trends N. 60° E. for about 500 feet 
and then follows a N. 10° E. course for the remaining distance over 
which it can be traced. At tLc bottom of the Virtue shaft a drift 
has been run northeast 12 feet and southwest 6 feet. A short crosscut 
also has been driven. Forty feet above the bottom a 60- foot drift 

Figure 17. — Map of the Woodward group of min- 
ing claims, north of Tyrone, N. Mez. 

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has been ran and 20 to 80 feet higher the Tein has been opened for 
40 feet. At 60 feet below the surface a stope has been op^ied to the 
southwest and carried to the surface. At the bottom the quartz vein 
is about 18 feet wide. On the next higher level a 16- foot crosscut 
had not yet reached the hanging wall. On the surface the vein 
varies in width and locally vein matter is intermixed with country 

The gangue mineral in the Contact vein is quartz, usually massive, 
though drusy cavities may be observed. The metalliferous minerals 
are pyrite, a little chalcopyrite, a mixture of manganese oxides (prob- 
ably pyrolusite and psilomelane) , and a silver and lead bearing sul- 
phide which is very fibaely disseminated in the quartz, is intergrown 
partly with pyrite, and appears in blotchy, grayish-black, cloudlike 
aggregates. A considerable quantity of this blotchy quartz was 
crushed to pass through an 80-mesh screen and most of the sulphide 
when examined under the microscope showed a lustrous black color. 
Some pieces showed a granular fracture, others had lustrous cleavage 
faces suggesting galena, and one piece seemed to be a crystal having 
faces combining a cube and an octahedron. When this material was 
examined qualitatively in the chemical laboratory for the presence of 
antimony, in order to prove, if possible, the presence of silver-anti- 
mony sulphides, a negative result was obtained, but a good test for 
lead and silver resulted. It seems probable, therefore, that the min- 
eral is finely granular argentiferous galena. Gold also is present, 
probably associated with the pyrite. The content of copper is not 
enough to make the mineral of commercial value. Locally, where the 
vein follows the fault plane, manganese is conspicuously abundant. 

The vein at its south end terminates against a strong fault which 
passes along the west face of the Little Burro Mountains. At its 
north end it becomes ill defined and there is some evidence that it 
passes into a system of smaller fractures, finally dying out entirely. 

The ratio of silver to gold values in the Contact vein is about 4 to 
1 when silver is 60 cents an ounce. The crosscut and drifts at the bot- 
tom of the Virtue shaft are reported to run 16 ounces to the ton in 
silver. The bottom of the shaft proper is reported to carry 42 ounces 
in silver and about $5 in gold to the ton. At another locality values 
as high as 126.8 ounces of silver and 0.64 ounce of gold are reported ; 
also 44 ounces of silver and 0.1 ounce of gold. 

The Casino vein dips steeply to the east (see fig. 17) and may be 
readily traced on the surface. The fracture is not a clean break 
throughout. Locally considerable country rock is admixed with 
quartzose material in alternating narrow bands, the whole being im- 
pregnated more or less with metallic sulphides. At a 110-foot shaft 
near the south end of the vein, where an old surface stope may be 
seen, the quartzose material varied in width between 5 and 10 feet 

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At one locality in this stope 8 feet of material, mostly quartz, was fol- 
lowed by 2i feet of brecciated vein matter against the hanging walL 
The values are said to be highest in the brecciated material. Rich 
streaks up to 18 inches in width and values up to 20 ounces of silver 
and $5 in gold to the ton across a distance of 5 feet were reported. A 
clay gangue next the hanging wall suggests a fault fissure. 

To the north on this vein the values in gold and silver are said to 
decrease, while zinc, lead, and copper values increase. Three-quar- 
ters of a mile north of the shaft just described the outcrop of the vein 
may be well seen in a small creek. Here the vein is about 10 feet 
wide but consists of a ribboned system of quartz stringers and coun- 
try granite. The mineralization is still strongest near the hanging 
wall, probably the locus of greatest disturbance at the time of Assur- 
ing. Chalcopyrite, pyrite, sphalerite, and galena are conspicuous 

Still farther north, at the Copper Sulphide shaft, 100 feet deep, 
the vein was worked for the galena and dialcopyrite. Values in 
gold and silver were reported low. An assay from this shaft is 
reported as follows: Silver, 4.7 ounces; gold, 0.04 ounce; lead, 5.9 
per cent; zinc, 10.2 per cent; copper, 2.1 per cent 

The Wyman vein has been worked over a distance of about 500 feet 
and not below a depth of 110 feet. The richest returns came from the 
part above a depth of 40 feet. Silver chloride and gold furnished 
the values in these upper levels. Zinc and copper are reported to 
have increased as greater depth was attained and gold and silver to 
have fallen to $3 to $5 a ton. In the upper portion of the vein much 
of the ore is reported to have assayed $200 to the ton. 

These veins are good examples of simple fissure fillings. In two 
of them, the Contact and the Casino, there is evidence of faulting; 
a part of the Contact vein undoubtedly follows a strong fault. Solu- 
tions carrying silica and metallic sulphides circulated through the 
fractures and deposited their load. Surficial alteration has played 
an important part in the enrichment of the deposits. The locally 
porous condition and the liraonite-stained quartz of the veins at the 
surface give evidence of this, and chlorides of silver and exceptional 
values in gold are reported from the upper parts of the Casino and 
Wyman veins. It is very clear that there is surface enrichment in 
these deposits and there should be changes of value in depth. How- 
ever, where unaltered galena, sphalerite, pyrite, and ddalcopyrite 
outcrop and where the quartz has not a stained or porous aspect 
assays at the surface are a fair indication of what may be expected 

The presence of manganese dioxide in these veins is interesting in 
the light of the recent contribution to the study of secondary enrich- 

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ment by W. H. Emmons,^ who shows that chlorine salts reacting with 
sulphuric acid will produce hydrochloric acid, which in the presence 
of manganese dioxide yields nascent chlorine, a solvent for gold. 

Emmons also points out that ferrous sulphate, a precipitant of 
gold, can not exist in the presence of MnOj or of higher manganates, 
and concludes that the gold will travel downward until a point is 
reached where no new sources of oxygen axe available and the excess 
of acid in ihe solutions is removed by reactions producing kaoliniza- 
tiaa. It is &t this stage that iron sulphate becomes increasingly 
prominent and effective as a precipitant of gold. 

Chlorides are reported from the upper levels of the vein described, 
and abundant MnO, may be seen locally on the surface. An explana- 
tion for the enrichment of the vein seems therefore to lie in the 
chemical reaction indicated above. 

The fissures which the veins fill are persistent along the strike and 
if they are not faulted will probably be found to persist in depth. 
The value of the veins, therefore, exclusive of their surface enrich- 
ments will depend directly on the assay values of the unaltered 
material and the persistence of such values in shoots of workable size. 
Naturally any values from the enriched upper portions will serve 
to balance lesser values as greater depth is reached. The Wyman 
vein indicates the depth to which alteration has taken place at one 
locality. Such a depth might differ considerably at another locality 
where the character of the gangue was not such as to favor the perco- 
lation of surface water. Solid quartz, for example, might prevent 

In the Ck>ntact vein, at the Virtue shaft, commercially valuable 
ores are known to a depth of 170 feet, and it is doubtful if enrichment 
has reached this depth. Therefore the ore may be relied upon to be 
of more even tenor, though of lower value, at considerable depth than 
at or near the surface. No one can predict the persistence of the 
shoots in the solid quartz. 


Three miles south of the summit of the Big Burro Mountains, on 
property owned by Theodore W. Carter, a strong quartz lode cuts the 
pre-Cambrian granite. The lode strikes about N. 85® E. and dips 
steeply south. It can not be traced east of the gulch east of the shaft 
but may be seen cutting the country rock to the west. A 150-foot 
shaft has been sunk and drifts run west along the lode, which is ex- 
posed by four crosscuts. It is reported to be 30 feet wide at the bot- 

^The agency of manganese on the superficial alteration and secondary enrichment of 
gold deposits in the United States, a paper read before the American Institute of Mining 
Bngineen at the Canal Zone meeting, November, 1910. 

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torn of this shaft. In a second shaft 50 feet deep the lode measured 
16 feet or more in thickness. The hanging wall is a narrow dike, 
probably a rhyolite. Pjrrite, chalcopyrite, secondary chalcoeite, ga- 
lena, and hematite are present. The total values in gold, silver, cop- 
per, and lead are said to aggregate $10 a ton. On the footwall in the 
60- foot shaft a banding or veining of the quartz may be seen, as if the 
quartz had entered along narrow, nearly vertical fissures. Much of the 
vein has a barren appearance and contains considerable hematite. 
The values are associated with the sulphides. The relations of this 
lode suggest considerable persistence in depth, but no prediction can 
be made as to the values which will be encountered- 



A number of prospects were examined within the area of pre^Cam- 
brian granite, in which iron and copper sulphides and gold occur in 
more or less well^-defined fracture zcmes. 

The properties which were visited are ttiose of Kmicky & Cosgrove, 
Natioaal Copper Co. (C. P. Laughlin) , Bc^iton A Wilson, R. P. Thom- 
son, and several prospects sontkeftst of the Big Burros. 

The claims of T. £. Enucky aad E. TSL Cosgrove are kxsted ^ 
miles almost due west of Tyrone and west of Whitewater Canyon. 
The examination of the writer was confined to the showings in the 
National shaft and at the dump of the Mayflower shaft 

The National doaft is 180 feet deep and for the lower 126 feet is 
an incline following a slip which strikes N. 70° E. and dips W S. 
The shaft is sunk in granite which, though fractured, shows no well- 
defined fissure to a depth of 55 feet, where the shaft turns to follow 
the slip mentioned. The upper 90 feet of the shaft is in oxidized 
ground, and scattering carbonates may be seen in vertical fractures. 
The lower 90 feet of the shaft passes through unoxidized pyrite, 
except that the above-mentioned slip contains a narrow seam or film 
of chalcoeite an inch or less in thickness. Enrichment processes have 
not operated extensively here. 

At the Mayflower shaft, about 2,000 feet west of the National shaft, 
some carbonates and much unoxidized pyrite were seen on the dump. 
The country rock is granite. The feldspar in the sulphide-impreg- 
nated granite is altered to sericite, the body of the sulphide-bearing 
rock being an aggregate of original quartz^ secondary quartz, sericite, 
and pyrite* 

It is reported that the unaltered sulphides were struck at a depth 
of 100 feet The shaft is 112 feet deep. No encouragement can be 
given that an ore body will be found at greater depth. 

The property of the National Copper Co. is located 3 miles due 
west of Tyrone, in a gulch at the head of Whitewater Canyon. At 

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this point a tunnel has been driven eastward into the hill for a dis- 
tance of 300 feet to strike a shear zone carrying chalcopyrite. At 
the end of this tunnel a drift has been run 47 feet south and 125 feet 
north. At a point in this drift about 60 feet north of the tunnel a 
winze was sunk 212 feet; at a depth of 100 feet a 90- foot crosscut 
was driven in the hanging wall and at the bottom of the winze a 
42-fbot crosscut was driven in the hanging wall. The main drift was 
in a dangerous condition from disuse and the winze was inaccessible. 
An examination of the face at the south end of the main drift showed 
no well-defined fracture zone. The material on the dump indicates 
that the deposit consists of chalcopyrite in a rather tight fracture 
zone. The chalcopyrite was accompanied in its introduction by 
quartz and calcite. Assays reported to the writer show a total yidd 
in gold, silver, and copper of $4.84 to the ton, with copper at 18 
cents. The value of this deposit depends on the persistence and size 
of the mineralized fracture zone. Little opportunity was afforded to 
examine it. 

The prospects of Bolton & Wilson are 4 miles west of Tyrone, on 
the east side of Iron Gukh and on the headwaters of Whitewat^ 
Canyon. A number of prospect pits were examined. The country 
rock is pre-Cambrian granite cut here and there by dikes of quartz 
monzcmite porphyry and by a few dark-colored dikes. None of the 
prospects were such as to give the impression that an ore body might 
be found. Ill-defined fissures or small fractures trend in general 
northward or northeastward, showing carbonate of copper near the 
surface and for a depth of 40 or 50 feet. Unaltered sulphides were 
struck near the surface. Pyrite, chalcopyrite, and quartz were the 
principal minerals of seccMidary introduction. Veinlets of chakoeite 
were seen and at one locality a little molybdenite filling fractures. 
Carbonate ores in paying bimches have been in the past extracted 
from some of the prospects. 

The property of R. P. Thomson is about If miles west of Tyrwae, 
in a small gulch running northward about one-fourth to one-third 
mile north of the quartz monzonite contact. A shaft 240 feet deep 
has been sunk in the granite and at 155 feet from the surface a cross- 
cut has been driven for 96 feet southeast. The shaft was not ac- 
cessible. The crosscut is reported to average 2 per cent of copper, 
mostly carbonates. The surface showings were very poor. 

About 3 miles southeast of Leopold and 2,000 feet southwest of 
Cherry Creek a 200-foot shaft has been sunk by the Cherry Creek 
Copper Co. in the pre-Cambrian granite. A little carbonate of cop- 
per is visible in the dump. Much specular iron is present in the 
material, at first sight suggesting chalcocite. 

Another shaft 70 feet deep, 6 miles almost due south of Leopold, 
was examined. Here a shear zone striking N. 75^ E. and dipping 

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86** S. traverses the granite. At the bottom of the shaft several 
tight seams were seen carrying oxidized cupriferous pyrite. Values 
up to $43 a ton are reported by John F. Jefford. A few hundred 
feet south on this ridge a drusy quartz lead carrying much hematite 
strikes N. 22° W. and dips 30° S. It is said to pan well in free gold. 
Other localities in the vicinity where prospect holes had been 
opened were seen, but the impression gained by a general survey of 
this pre-Cambrian area is not encouraging for extensive deposits. 
Undoubtedly gold-bearing sulphide-quartz stringers have been sur- 
ficially enriched, but the level of unoxidized pyrite is shallow. Small 
stringers will not pay when the unoxidized pyrite is reached. None 
of the localities visited gives hope of a copper deposit of workable 




The type of secondarily enriched ore body, so well known in the 
Southwestern States, has already been the subject of a number of 
detailed researches by Lindgren and others. As compared with such 
work the following notes are but an outline indicating the important 
geologic and mineralogical relations. This type, in that it is depend- 
ent for its origin on sulphide mineralization of fractured porphyry, 
has much in common with the less important deposits just described ; 
but in that the mineralization was far more thorough and the process 
of enrichment far more extensive, it is decidedly different Likewise 
it differs in being associated with a rock type which is curiously 
prolific of such deposits at many other localities. For the sake of 
clarity, and in view of the fact that these ore bodies are more exten- 
sively developed than any others in the immediate region, a slightly 
more systematic treatment will be accorded them than has been fol- 
lowed in the preceding pages. 

The chalcocite deposits of the Burro Mountains lie at the foot of 
and on the northeast side of the Big Burro Mountains. Four com- 
panies were developing the field at the time of the writer's visit — ^the 
Burro Mountain Copper Co., the Chemung Copper Co., the Savannah 
Copper Co., and the Mangas Development Co. The writer wishes to 
express his thanks for the courtesies extended to him by the operators. 
The information obtained from them was of special value in the 
preparation of this brief account of the chalcocite ore bodies. 

The offices of the several operating companies are located at or 
near the mining camps of Leopold and Tyrone. The writer was 
fortunate in having an opportunity to examine the mines as well as 
to study a nimiber of drill records. It is the purpose of this descrip- 
tion to present tiiose geologic relations which have a bearing on the 

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distribution of this type of ore body in this region, without giving a 
drtailed account of individual mines.^ The facts which are presented, 
it is hoped, will aid in a clearer understanding of the principles that 
determine the locus of the ore. Needless to say, the larger operators 
are already in possession of such an understanding. It is therefore 
for those not yet acquainted with the region and for those who may 
not have had an equal opportunity to study the district that the 
facts are presented. 


The first and salient fact connected with the occurrence of the 
chalcocite ore bodies near Leopold and Tyrone is the intrusion of a 
mass of quartz monzonite of subcircular outcrop into a pre-Cambrian 
granitic complex (see map, PI. IV, p. 132), for the important chal- 
cocite ore bodies are connected with this intrusive rock. 

The pre-Cambrian complex comprises various types of coarse to 
medium grained granites and associated porphyry and pegmatitic 
dikes, with still later rhyolitic dike and stocklike intrusions. The 
quartz monzonite is a medium to coarse grained granular rock of 
rather light appearance where fresh. Both even granular and por-. 
phyritic phases are present, and dikes of nearly the same composition 
as the main mass are locally abundant. These dikes are later than 
the main mass and are characterized by very large phenocrysts of 
feldspar, some an inch or more in length. 

The quartz monzonite where coarsely granular is composed of 
quartz, oligoclase and orthoclase feldspar, and a subordinate amount 
of biotite and hornblende. The oligoclase crystals are fairly well 
formed and many of them are partly inclosed in crystals of orthoclase 
and quartz. Sphene, apatite, magnetite, and a little chlorite are 

The porphyritic phases contain phenocrysts of oligoclase, with 
perhaps a little andesine and albite, and of biotite embedded in a 
fine mosaic of quartz and orthoclase with a little twinned feldspar. 
Quartz makes up about half of the groundmass. Apatite, sphene, 
and magnetite are accessory minerals. 

In both the even-grained and porphyritic phases of the quartz 
monzonite the biotite mica is noticeable in hand specimens, its lus- 
trous black color contrasting strongly with the otherwise light 
appearance of the rock. In the ore-bearing zone, however, the mon- 
zonite takes on a quite different appearance; it is iron stained, 
fractured, and silicified; the biotite has generally disappeared*; 
kaolinization of the feldspars is prominent, and hills in this zone have 
a characteristic rough, jagged, gossan-like appearance. 

^A description of this territory and an account of some of the mines operated in the 
past is published in Prof. Paper U. S. Geol. Survey No. 68, 1010, by Waldemar Llndgren, 
L. C Graton, and C. H. Gordon. 

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The second important condition affecting the locus of the ore 
deposits is the intensity and distribution of the fracturing of the 
quartz monzonite. Where solid and unaltered this rock does not 
carry ore. Where intensely fractured it carries ore. There is 
a distinct and traceable gradation from the zone of intense frac- 
ture to the areas of essential solidity, and the surface exposure 
of the fractured mass has a comparatively definite form. It may 
be represented as a triangle pointing southwest, its point approxi- 
mately 1^ miles southwest of Leopold and its base formed by a 
line passing from Tyrone to Oak Grove. The line of greatest frac- 
ture lies between Leopold and Tyrone and forms roughly the north 
side of the triangle. This north edge follows for a portion of the 
distance the contact between the quartz monzonite and the pre-Cam- 
brian granites to the north, and present data seem to indicate that 
mineralization of this type is not extensive north of this contact. 
(See map, PL IV, p. 132.) 

Southward from this zone of greatest fracture the rock gradually 
becomes more solid and less altered. The fracturing fades away 
toward the south in a manner suggesting the opening of a fan, placed 
parallel to the locus of greatest fracture, with its handle southwest of 
Leopold, and so opening that one edge of it swings as a radius, with 
the handle as a center, through the arc of the triangle. On the south- 
ern edge of the imaginary triangle the fractured rock merges very 
imperceptibly with the essentially solid quartz monzonite. 

In the above description only the horizontal distribution of fractur- 
ing has been considered. There is reason to believe that certain 
elements affecting the depth of the ore bodies are directly due to the 
arrangement of the fractures. 

A study of the mines shows clearly that the depth to which oxida- 
tion has penetrated the rocks increases in a northeasterly direction, 
viz, from Leopold to Tyrone — and, further, that toward the south the 
dip ajid strike of the fractures shift. In the region about Tyrone, for 
example, the strongest fractures observed in the mines strike north- 
easterly and dip at different angles to the south. There are, it is true, 
innumerable fractures which do not follow this rule, notably vertical 
ones which cut the eastward-dipping system, but the fracturing is 
dominantly northeast with a southerly dip. On the other hand, on 
the southern border of the fractured zone the dominant fractures 
strike east, with a northward dip, though here also many other frac- 
tures are found. It should be stated that some of the strong fissures 
in the mines represent fault planes and that the contact of the quartz 
monzonite with the granite between Tyrone and Leopold follows for 
a distance such a fault, (See PL IV.) 

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Considering a number of these fissuree, tliea» as fault planes, we may 
readily see that a pyramid-shaped block is involved in the ore-bearing 
zone and that while the limiting fractures of this block (those near 
the northern and southern edges) will meet at the surface near the 
point of the pyramid, they will meet at increasing depths as distance 
from the point is gained. (See fig. 18.) It must not be understood 
that any such regular fractures exist as are shown in the diagram, 
but it is a fact that the dominant strikes and dips are so distributed as 
to suggest such a figure as is presented. It would be expected that 
percolating water under the influence of such a system of breaks would 
tend to migrate down the planes of the breaks and would move toward 
the zone of most intense fractura Such seems to have been the ease, 
for deepest oxidation has taken place near Tyrone. 

FiGCKB 18. — Stereogram showing bow the juncture of two systemR of east-west and north- 
eMt-M«lhw«pt fractnree dlpplnc toward each other will become lower to the east 


The present conditions of the ore bodies so far as mineralization is 
concerned may be attributed to three processes — ^primary mineraliza- 
tion, enrichment, and leaching. 

Primary mineralization consisted in the deposition of cupriferous 
iron pyrite (probably finely intergrown chalcopyrite with pyrite) and 
locally quartz. The introduction of the pyrite followed the fractur- 
ing of the quartz monzonite. The solutions which carried the sul- 
phides not only deposited their burden in the innumerable fractures 
but likewise soaked into the body of the rock. Deposition was greatest 
along lines of easiest passage, viz, in well-defined fissures. At the 
dose of the period of deposition of the primary ore the mass of the 

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rock consisted of a network of veins and veinlets of iron pyrite, with 
locally quartz and a little chalcopyrite. The feldspar of the rock 
was much altered to sericite and the ferromagnesian minerals were 

The formation of ore bodies from this stockwork of pyrite veins 
was clearly a result of secondary enrichment. An opportunity for 

FiouRB 19. — Sketch showing sloping plain at the foot of the Big Burros, now dissected, 
cut during the Quaternary cycle of erosion, and the gravels which fill the Mangas 
Valley, a. Big Burros ; h, dissected sloping plain ; c, gravel of Mangas Valley, formed 
in part by the erosion of the sloping plain. 

such enrichment was afforded before and during the Quaternary 
cycle of erosion, in which were laid down those widespread deposits 
of gravels and sands which now fill the Mangas Valley and the coun- 
try to the east and south. One standing on the summit of the Little 
Burros and looking toward Tyrone can easily recognize the dissected 

sloping rock-cut platform 
which circles the Big Burros 
and merges with the gravel 
deposits at its outer edge. 
(See fig. 19.) 

The process of enrichment 
is well known, and consists 
first in the oxidation of the 
unaltered pyrite near the sur- 
face by surficial waters and 
second in the deposition of 
chalcocite at lower levels by 
downward-percolating water, 
which in the main carried 
copper in a sulphate solution. 
The junction of several fis- 
sure systems and the local 
damming of percolating wa- 
ters against relatively impervious dikes have tended to produce 

A microscopic examination of a number of thin sections cut from 
sulphide-bearing rocks in the mine of the Chemung Copper Co. shows 
rather plainly certain of the stages in the formation of the chalcocite. 
Figure 20 shows a small group of pyrite crystals embedded in a 
microcrystalline aggregate of sericitized feldspar and quartz. Much 
of the quartz is probably secondary. Abundant prisms of apatite 

Figure 20. — Group of pyrite crystals, showing 
chalcocite along the edges, embedded in seri- 
citized feldspar and quartz. 


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are present. Chalcocite has formed on the edges of the pyrite. Fig- 
ure 21 shows in addition the presence of kaolin associated with the 
pyrite- The parallel kaolin bands shown in the figure probably 
follow the twinning planes of a plagioclase feldspar phenocryst now 
almost entirely altered to a mass of sericite. Figure 22 shows a small 

veinlet, in sericitized feld- 

spar, filled with chalcocite, 
pyrite, and a little quartz. 
Figure 23 shows another vein- 
let cutting feldspar in which 
a nodule of pyrite is sur- 
rounded by chalcocite; a lit- 
tle quartz is present. Near 
this veinlet may be seen 
grains of unaltered sulphide. 

In other specimens the 
rock is speckled with grains 
of unaltered pyrite, near 
which are chalcocite grains, 
some without any signs of 
the original pjrrite and some 
showing partial replacement. 

It is a characteristic fea- 
ture of this district that 
much of the ore-bearing ter- 
ritory has been thoroughly 
leached, near the surface, of its copper content ; that is, all the copper 
has gone down and only a siliceous, ferruginous capping remains. 
Locally this leaching has been carried to great depths, 700 feet or 
more. This process of leaching, which is simply a step in the for- 
mation of a secondary chalcocite ore body, is unfortunately also 

capable of destroy- 

FiousB 21. — Kaolin associated with chalcocltlza- 
tion of pyrite. 

Sericitized feldspar 

'v. Pyrite 

ing an ore body 
and has done so in 
a number of places 
■ in the territory ex- 
amined. Portions 
of strong veins of 
chalcocite are lo- 
cally leached, noth- 
ing remaining of 
the original mineralization except a network of limonite veins. The 
disseminated stockworks also are locally so impoverished as to pre- 
clude their extraction at the present price of copper. This process 
of late leaching is well shown in some places where vertical fractures 
cut across eastward-dipping veins. (See fig. 24, p. 147.) 
94174«»— BuU. 470—11 ^10 

Figure 22. — Small veinlet In sericitized feldspar filled with 
chalcocite, pyrite, and quartx. 

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Although developments have shown that as a rule leached veins 
will lead at greater depths to enriched ore bodies, it is also dear that 
this is not always the case, for solutions may carry copper great dis- 
tances, perhaps to such depths that it ceases to be profitable to con- 
tinue a search. Definite prediction that a certain block of leached 
ground will yield an ore body at a given depth is impossible. To 
determine this point, a drill hole or a shaft is necessary. 

The thickness of the blanket of barren ground overlying the ore 
bodies is extremely variable. In the country southeast of Leopold 
it varies from a few feet to 500 feet Near Leopold there is reason 
to believe that the topography of the surface affects the upper limit 
of the ore. For example, an ore body to a certain level will 

pass horizontally into 
leached ground, as a 
gulch on the surface 
is approached — that is, 
locally leaching is at 
lower levels directly be- 
neath stream channels. 
Near strong veins and 
faults, too, leaching is 
deeper than in the 
adjacent ground. The 
thickness of the chal- 
cocite zone also is 
variable. Southeast of 
Leopold unaltered sul- 
phides are struck lo- 
cally at a depth of 380 
feet, above which is 
180 feet of secondarily 
enriched ground. The 
leached ground there- 
fore is 200 feet deep. Again, a drill struck unaltered sulphides at 
2S0 feet, and at another locality unaltered sulphides appear at 300 
feet. The ground carrying chalcocite is locally 200 to 300 feet thick. 
In the Tyrone country leaching is locally very deep, 700 feet or more. 
Permanent water level also is variable, standing 800 to 500 feet 
beneath the surface. It may vary as much as 200 feet in half a mila 
The amount of water increases rapidly as the footwall fault near 
Tyrone is approached, indicating increased flowage near such breaks 
and accounting for the deeper leaching adjacent to them. 

What has been said indicates that from their very nature irregu- 
larity is to be expected in the shape and size of the ore bodies, for the 
depth to which enrichment has penetrated is variable and also the 
amount of leaching which followed such enrichment 

' -^ • I ' Quartz '/ tZ 

FXQUKB 23. — VeUIet showing nodale of pyrite surroonded 
by ehalcoelto. 

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Broadly considered, the ore bodies that have been best developed 
fall into two classes — ^those which are directly connected with veins 
and those which are not. Of the former several have been worked 
extensively in the territory southeast of Leopold, and mudi rich ore 
was extracted. In the mines near Leopold and Tyrone also much 
ridi ore has been extracted from veins. The second class includes 
cigar-shaped masses of chalcocite ore and irregularly shaped blocks 
of ground grading oflf at the edges into rock too poor to be commer- 
cial. This grading off into lean material is in some places due to a 
change to unaltered sulphides, in others to a change to leached 
material. A number of 

these ore bodies are sev- £ 

eral hundred feet in 
length, breadth, and 

The material consid- 
ered ore in these mines 
varies in copper content 
from 2.5 to 8 per cent 
As a rule the costs of 
mining and price of 
copper will determine 
when an ore body will 
cease to be profitable to 



FiouRB 24. — Sketch showing leaching of eastward-dipping 
chalcocite veins along later rertical Teins carrying 
only limonlte. 

At the time of the 
writer's visit develop- 
ment by the Savannah 
Copper Co. was confined to drilling. A number of mines now closed 
but worked in the past are controlled by this company, but it was not 
practicable to study the underground workings. The more important 
shafts are located on Plate IV (p. 132), and the notes given below will 
indicate the character of the deposits. The Mangas Development Co. 
also confined its operations to drilling. Active development by drift- 
ing and shaft sinking was under way only on the property of the 
Burro Mountain Copper Co. and the Chemung Copper Co. 


The offices of the Savannah Copper Co. are located half a mile 
nearly east of Leopold. The Boone shaft is 300 feet deep and con- 
nects underground with the Oquaqua shaft, about 900 feet to the 
north-northwest. The Boone shaft develops a nearly vertical vein 
trending north-northwest The vein has not been worked above the 
260- foot level. It varies from a few inches to 10 feet in width. All 

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the ore was taken from the 250-foot level over a distance of about 
600 feet. Stoping did not exceed 30 feet above the level. Winzes 
15 to 20 feet deep were opened. The mine run yielded 5 per cent of 
copper, and hand-sorted stringers gave 10 or even 20 per cent values. 

The Oquaqua shaft is 300 feet deep and opens about a mile of 
underground work. No ore was found in the workings except a 
vein 3 or 4 feet wide with enrichment in the walls up to 2 per cent 
for 16 to 20 feet This vein, trending N. 80^ E. and dipping 60** N., 
was followed for 600 feet and crosscut four times. A winze 40 feet 
below the level began to reach unaltered sulphides. Carbonates and 
iron gossan descend to 200 feet at this locality and unaltered sul- 
phides are found at about 380 feet. 

The EHondike shaft, about 1,800 feet nearly north of the Oquaqua 
shaft, is 300 feet deep. It cuts a north-south vein dipping 60° E. 
at 250 feet. At this depth a drift was driven 150 feet and some 
crosscutting done. But little ore was found. Unaltered sulphides 
were reached at 800 feet. Most of the values were in the carbonates 
and were taken out near the surface. Among the other properties 
idle at this time was the Virginia, located about one-third mile east- 
southeast of Leopold. Here a northeast lode, dipping 50° north- 
west, has been explored by a vertical shaft reported to be 200 fe^t 
deep. Some good ore was taken out previous to 1905, and the mine 
has had some production since that time. 

There are a number of other old workings on the Savannah Co.'s 
ground, but they need not be mentioned here. The company is at 
present engaged in exploring its ground by chum drills. 


The property of this company has been operated since 1901 or 1902, 
and active production has been in progress from 1903 or 1904 to the 
present time. About 1905 the property was acquired by Phelps, 
Dodge & Co. The main shaft is in Leopold, and a second shaft, the 
Boston shaft, is located one-third of a mile east-northeast of town. 
The workings have attained a depth of about 400 feet, with a winze 
level at 500 feet. Four ore bodies have been more or less devel- 
oped — the Protection, the West Sampson, the East Sampson, and 
the East. The first three of these bodies have a very definite orienta- 
tion of their long diameters. They trend northeast, are arranged 
roughly en echelon, are longer than wide, and each shows to a greater 
or less degree that the mass of enriched material is lenticular in 
form. The East ore body has more noticeably the form of an irregu- 
lar cone pointing downward and northeastward. It is connected 
with the East Sampson by a narrow neck. 

"While unaltered pyrite has been encountered at the extreme west 
end of this group, the bottom of the chalcocite zone has not been en- 


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cotmtered elsewhere. The values in the lenses hold up well along 
vertical lines through their centers hut fall gradually as the ends 
are approached. 

In this mine the St. Tjouis vein, a well-defined fissure dipping east 
and considered the footwall fissure, as all the ore bodies are east of it, 
has produced much rich ore in the past. It is the only very strong 
fissure to be seen in the mine. The Protection ore body is said to be 
developed on this vein. There are numberless smaller veins, however, 
some of which are undoubtedly small faults. In one place a body of 
ore was sharply cut off by such a fault. Large ore reserves are present 
in the mine, as much of the work done is in the nature of develop- 
ment. The company is sinking a new shaft, about midway between 
the mines at Leopold and Tyrone. At Leopold a 300-ton concentrat- 
ing mill has been operated at intervals for several years. Only de- 
velopment work was done in 1910. 

xzvsa or the oKEmrva coppeb oo. 

The principal workings of the Chemung Copper Co., located at 
Tyrone, are opened by two shafts. No. 2 and Na 3. Shaft No. 1 is 
not connected with the main workings. 

Shaft No. 2, 722 feet deep, is located about half a mile nearly south 
of Tyrone in a small gulch entering the gulch on which Leopold and 
Tyrone are located. Shaft No. 3, 421 feet deep, is one-fourth mile 
farther south, up the same small gulch. The underground workings 
include about 8 miles of tunnels, drifts, raises, and winzes. All the 
ore extracted is on the dumps, none having ever been shipped. 

Ore in the Chemung mines occurs both in veins and in large blocks 
of more or less ore-bearing ground, the boundaries of the ore bodies 
depending on the degree of leaching which has taken place. From 
shaft No. 3 the ore zone pitches almost due east, spreading and split- 
ting up as it gains depth. What is called the hanging- wall fault is a 
persistent break which has been developed in the mine over a horizon- 
tal distance of 2,750 feet. The fault dips from 45° to 50° E. and 
strikes about northeast. It is definitely enriched both in the fissure 
and in the adjacent walls, though locally it is thoroughly leached. 
The mine has developed a number of veins that are quite distinct from 
the disseminated ore bodies. In some of these veins values of 12 per 
cent or more are found. The presence of ore in disseminated bodies 
to the east of the hanging wall proves the possibilities east of that 

West of shaft No. 2 the groimd is leached, and as the so-called foot- 
wall fault is approached water increases noticeably — in fact, a very 
strong flow develop's, sufficient to prevent for the present the develop- 
ment of the territory immediately adjoining the fault The waters 
are highly impregnated with copper salts. 

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Though imoxidized pyrite is locally found in this mine, leaching 
reaches a remarkable depth, being proved to exist on the 800-foot 

The ore which has been hoisted from the mine will average a little 
higher than 8^ per cent It is reported that by reducing the limit 
to 2} per cent the ore reserves could be increased by one-half. 


To simmiarize, the following geologic facts are important in their 
bearing on the extent and distribution of the chalcocite ore bodies 
near Tyrone and Leopold : 

The ore is for the most part in the quartz monzonite. Though some 
granite is present in the Tyrone mines and though this rock contains 
ore, it may be said that the contact of the quartz monzonite with the 
granite marks the northern edge of the ore-bearing zcme. 

The distribution of the ore is directly dependent on a system of 
fractures. The fractures roughly take flie form of a triangle whose 
point lies southwest of Leopold. The dips of the fractures to the 
south in the northern part of the area and to the north in the south- 
em part of the area tend to make the fractures deeper toward the 
east. The more highly fractured region lies between Leopold and 
Tyrone. The number of fractures diminishes to the south, and there 
is a corresponding diminution in the richness of the disseminated ores, 
though not of individual veins. 

The primary deposition of ore seemed to be governed principally 
by the fractures. Dikes within the ore-bearing zone, if fractured, 
carry ore ; if not fractured they do not carry ore. The richest ore 
bodies are found in the zone of greatest fracture or along well-defined 
veins. The junction of several systems of veins tends to increase the 
value of the ores; dikes also have locally acted as dams to percolat- 
ing waters and thus increased the precipitation of secondary ores. 
Ore of this type will probably not be found in areas of fairly solid, 
relatively unoxidized quartz monzonite. 

The ore bodies are essentially secondarily enriched cupriferous 
pyrite deposits in veins and in stockworks. 

The depth to unaltered sulphides is variable and in general in- 
creases to the east When the level of unaltered primary pyrite is 
clearly reached, no enriched ore can be expected beneath it Indi- 
vidual enriched veins may penetrate the general level of primary 

Leaching of the ore bodies has locally impoverished them; and 
though in general a leached area indicate commercial ore at greater 
depths, yet here and there leaching may extend to d^ths consider- 
ably below the principal ore horizon. 

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By W. H. Emmons and F. B. Lanby. 


The mineral deposits of Ducktown, Tenn., are located in the south- 
cast corner of the State, near the North Carolina line, and extend 
southward into Georgia. The deposits were discovered in the late 
forties and, except during a brief interval in the early sixties and a 
longer one from 1877 to 1890, mining operations have been carried 
on continuously since their discovery. They had produced to the end 
of 1909 over 190,000,000 pounds of copper, about 1,500,000 tons of 
iron ore, and a relatively small amount of silver and gold. They 
yield at present, in addition to the metals, about 650 tons of sulphuric 
acid daily. Two companies are operating in the district, each having 
its own smelter, railroad, and acid plant. These are the Tennessee 
Copper Co., with headquarters at CopperhilL and the Ducktown 
Copper, Sulphur & Iron Co., with headquarters at Isabella, about 
3 miles north of Copperhill. The production of copper in 1909 was 
19^07,747 pounds.* 

The district is included in the mountainous area of the southern 
Appalachians, and the greater portion of it is a small intermontane 
plateau about 1,600 feet above sea level, which is neariy surrounded 
by mountains that rise from 1,000 to 2,000 feet higher. This moun- 
tainous district is an area of complex geologic relations and extensive 
metamorphism. The region surrounding Ducktown has been mapped 
by Keith,* Hayes,' Hayes and Campbell,* La Forge and Phalen,* 

^ Batler, B. &., Mineral Resources U. S. for 1009, pt. 1, U. S. Qeol. Sanrey, 1911, p. 171. 

> Keith, Arthur, KnozTUle folio (No. 16); London folio (No. 26); Nantahala folio 
(No. 148), Oeol. Atlas U. S., U. 8. Oeol. Surrey. 

•Hayes, C. W., Clevelaiid folio (No. 20), Geol. Atlas U. S., U. S. QeoL Suirey, 1895; 
Physiography of the Chattanooga district In Tennessee, Georgia, and Alabama : Nineteenth 
Ann. Bept U. 8. Qeol, Surrey, pt 2, 1899, pp. 1-58. 

« Hayes, C. W., and Camphell, Bl. B., Geomorphology of the soathem Appaladiians : Nat. 
Geog. Mag., vol. e, 1894, pp. 63>126. 

■La Forge and Phalen, BUlJay folio (In preparation), U. 8. Oeol. 8«rrey. 


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and others. The mineral deposits also have been described in several 
papers/ which together afford a great fund of useful data on the 
occurrence and genesis of the ores. 

The work on which this paper was based was done in the summer 
of 1910, from May 1 to August 31. Mr. Laney was engaged during 
the greater portion of that period in areal mapping of the district 
and in stratigraphic studies in fields near by. The ore bodies were 
mapped and studied by Mr. Emmons. The result of the investiga- 
tions will appear in a joint paper on the geology and ore deposits of 
the district. The present paper is simply a preliminary statement of 
the principal economic results, and it may be necessary to modify the 
conclusions when the study shall have been completed. 

The writers wish to express their thanks to Mr. Waldemar Lind- 
gren and to Mr. Arthur Keith for valuable suggestions in the field, 
and to Messrs. N. H. Emmons and M. A. Caine, of the Tennessee 
Copper Co., and Messrs. C. W. Renwick and J. H. Taylor, of the 
Ducktown Copper, Sulphur & Iron Co., for much valuable informa- 
tion and for many courtesies. 



The region including the Ducktown district has been described in 
the several papers cited above. The folio describing the Nantahala 
quadrangle,' which is east of the Ducktown district, was published in 
1907. In this folio are brought together in concise form the descrip- 
tions of the formations and the salient features of the geologic history 
of the province as a whole. The text of the folio has been freely 
drawn upon in the outline of the geology which follows. 

The mountainous area of eastern Tennessee is composed of igneous, 
sedimentary, and metamorphosed rocks which range in age from pre- 
Cambrian to Carboniferous. These rocks have nearly everywhere 
been closely folded, at many places they have been complexly 
faulted, and some of them have been profoundly metamorphosed by 
pressure at great depths. The major faults, the axes of the folds, and 
the schistosity developed by metamorphism trend as a rule toward 
the northeast. The rock formations outcrop as parallel belts, and 

1 Safford, J. M., Geology of Tennessee, NashTille, 1860, pp. 46&--482. Whitney, J. D., 
BemarkB on changes which take place In the structure and composition of mineral veins 
near the surface, with particular reference to the east Tennessee copper mines: Am. 
Jonr. 8ci., 2d ser., yoL 20, 1855, pp. 53-^7. Ansted, D. T., On the copper lodes of Duck- 
town in east Tennessee: Quart. Jour. Oeol. Soc., vol. 13, 1857, pp. 245, 254. Heinrlch, 
Carl, The Ducktown ore deposits and the treatment of the Ducktown copper ores : Trans. 
Am. Inst Min. Bng., Tol. 25, 1806, p. 173. Kemp, J. F., The deposits of copper ores at 
Ducktown, Tenn. : Trans. Am. Inst. Mln. Eng., vol. 31, 1902, p. 244. Weed. W. H., 
Types of copper deposits In the southern United States : Trans. Am. Inst Min. Eng., Tol. 
80, 1001, p. 480. 

•Keith, Arthur, Nantahala folio (No. 143), Geol. Atlas U. S., U. S. Qeol. Survey, 1007. 

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where the softer rocks have been eroded the lowlands and valleys are 
formed, leaving the more resistant rocks as ridges or mountain ranges, 
most of which trend northeastward like the major structural features 
of the country. 


The oldest formation is the Carolina gneiss, a great series of 
schists and gneisses which probably represent for the most part the 
metamorphosed equivalents of granite and other igneous rocks, 
though certain phases are regarded as metamorphosed sedimentary 

The Boan gneiss is associated with the Carolina gneiss in relations 
which seem to imply that it is intrusive in that formation. It has 
been extensively metamorphosed, but certain phases of it are not 
so highly schistose as the Carolina. It is probable that most of this 
gneiss was diorite and gabbro. Both the Carolina and the Roan are 
intruded by granite which, though locally schistose, has not be^a 
subjected to the profound metamorphism that affected the gneisses. 


Hiwassee slate, — ^Resting unconformably upon the gneisses and the 
granite is a great series of sedimentary rocks consisting of gray- 
wackes, grits, conglomerates, shales, and limestonea Cambrian fossils 
have been found well toward the base of this series. The oldest form- 
ation of this series in the Nantahala quadrangle is the Hiwassee slate. 
This consists of banded slate and sandy shale, and its thickness is 
probably about 500 feet. It is much thicker than that where exposed 
in the Murphy quadrangle, in the gorge of Hiwassee River. 

The Wilhite slate, the Citico conglomerate, and the Pigeon slate, 
of Hayes, which are exposed in the southeast comer of the Cleveland 
quadrangle, are regarded as the equivalents of the Hiwassee.^ The 
Wilhite, though consisting in the main of dark slate, carries lenses 
of gray siliceous or argillaceous limestone^ which grades into cal- 
careous slata Some limestone conglomerates are associated with the 
limestone and have evidently been derived from them. Interbedded 
with the slates are beds of sandstones and conglomerates and locally 
these attain considerable thickness. At most places in this area the 
Hiwassee is closely folded, and its thickness can not be stated with 
even approximate accuracy. 

Great Smoky formMion. — ^The Great Smoky formation is a thick 
series of rocks extensively developed in the Great Smoky Mountains. 

1 Keith, Arthur, Nantahala folio (No. 143), Geol. Atlas U. S., XT. S Geol. Surrey, 
1907, p. 11. 

'Hayes, C. W., Cleveland folio (Na 20), GeoL Atlas U. 8., U. 8. GeoL Surrey, 
1808, p. 2. 

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Generally it oyerlies the Hiwassee slate, but in acme places it over- 
laps the Hiwassee and rests directly upon the Carolina gneiss. The 
formation includes conglomerate, graywacke, grit, sandstone, quartz- 
ite, mica schists, garnet schist, and slate. The conglomerates, grits, 
and sandstones are greatly in excess of the more highly alu- 
minous layers. These grade one into another along the beds and 
across them. The whole series may be described as an association of 
beds of the different sedimentary rocks. Feldspar is a prominent 
constituent of nearly all the gritty layers, although it is somewhat 
subordinate to quartz. In the Ducktown region few of the pebbles 
are more than one-fourth inch in shortest diameter, though some 
of them are half an inch long. Some of the conglom^^te bands 
contain a few flakes and flat pebbles of dark slate, presumably derived 
from associated slatea 

The slaty beds are composed' of finely comminuted material of sedi- 
mentary origin. Even in these there is a very large proportion of 
quartz and some feldspar. There is probably not much clay in any 
'of the beds and if they have be^i derived from muds, it would seem 
that such muds had not been greatly changed by weathering. The 
Great Smoky formation has been closely folded and at some places 
converted to schist. Some layers have been changed to bands con- 
taining large amounts of garnet, staurolite, and other metamorphic 
minerals. Those containing abundant staurolite crystals appear to be 
fairly persistent and some of them may be traced over great distances. 

Deformation is such that the thickness of the Great Smoky forma- 
tion can not be accurately measured, but the best estimate available 
places it at nearly 6,000 feet. 

Nantahala date. — ^The Nantahala slate, whidi overlies the Great 
Smoky formation, is composed of black and gray slates and of schists 
containing mica, garnet, staurolite, and ottrelite. Near the base 
these strongly resemble the slate and schist beds in the Great Smoky. 
The basal part of the Nantahala resembles the Great Smoky in that 
it carries many sandstones and conglomerates. Higher up in the 
formation there are also unimportant layers of graywacjce and con- 
glomerate. The thickness of the formation in the Nantahala quad- 
rangle is from 1,400 to 1,800 feet. 

Tusquitee quartzite, — ^The Tusquitee quartzite, which lies C(mform- 
ably above the Nantahala slate, consists chiefly of white quartzite 
which contains locally a few seams of fine ccmglomerate. At some 
places the component minerals are mashed and recrystallized. This 
formation is in general from 50 to 200 feet thick, but locally it 
reaches a thickness of 500 feet. 

Brasstown schist. — ^The Brassbown schist overlies the Tusquitee 
quartzite and consists mainly of black or bluish-gray ottrelite schisti 

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with a Tarying thickness of banded slate containing little or no 
ottrelite. The schist has been subjected to various degrees of meta- 
morphism. Locally garnet and staurolite are developed. 

VaUeytawn formation. — ^The Vallejrtown formation, which overlies 
the Brasstown sdiist, ccmsists of graywacke and fine-grained gneiss 
interbedded with dark garnet and ottrelite schists. In the basin of 
Valley River mica schist and fine-banded gneiss constitute iH*acti- 
cally all of the formation. The beds are most unif (M-m along Nanta- 
hala River, where they are apparently from 1,000 to 1,200 feet thick* 

Murphy fnarble, — ^The Murphy marble, which overlies the Valley- 
town formation, is a white, blue, or white and blue recrystallized 
limestone. Where the base is exposed it passes downward into the 
Valleytown by interbedding with the slates of that formation. It 
passes into the overlying Andrews schist through interbedded 
marble and schist. The thickness ranges from 150 to 500 feet. 

Andrews schdat. — ^The Andrews schist consists of a bed of calcareous 
schist from 200 to 350 feet thick. It contains ottrelite, muscovite, 
biotite, and other minerals. Brown hematite is interbedded with 
the schists and occurs also as lumps and masses in the residual clay. 

Nottely quartzite. — ^The Nottely quartzite, which is the highest 
Cambrian formation exposed in the Nantahala quadrangle, originally 
consisted of quartz sand and feldspathic material. During meta- 
morphism this was replaced by secondary quartz and muscovite. In 
some places the mica flakes become coarse and the rock approaches 
quartz schist in appearance. The formation is at least 150 feet thick. 


All the Paleozoic formations which have been described are of 
Cambrian age and all are exposed in the Nantahala quadrangle, 
which joins the Murphy quadrangle on the east. It is not known 
that the Nottely quartzite is the last formation deposited in that 
area, for the record of sedimentation may not be complete in the 
Nantahala quadrangle. Keith ^ has correlated the Valleytown forma- 
tion of the Nantahala quadrangle with the Hesse sandstone of the 
Loudon and other quadrangles. In the Loudon quadrangle, which is 
just north of the Murphy quadrangle, there are above the Hesse 
about 1,500 feet of Cambrian limestone, sandstone, and shale, ex- 
clusive of the Knox dolomite, about 3,500 feet thick, which is 
regarded as in part of Cambrian age. Above the Eoiox in the 
Loudon region is a considerable thickness of Silurian, Devonian, 
and Carboniferous strata which have been almost if not completely 
removed in the mountainous area. From the base of the Cambrian 

1 Nantahala folio (No. 143). Geol. AtUs U. &, U. 8. Geol. Survey, 1907, p. 11. 

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to the top of the Great Smoky conglomerate the thickness of strata 
is about 6,000 feet; from the top of the Great Smoky to the Nottely 
quartzite it is about 5,300 feet; and from the Nottely quartzite to the 
top of the Carboniferous it is about 9,600 feet. These figures are 
not accurate^ for the several formations feather out here and there, 
and there is no certain record that some of them ever covered the 
Ducktown district, but they convey an idea, probably not exagger- 
ated, of the great thickness of the Paleozoic rocks in this region. 
As the contacts of the various formations are not knoivn to show 
angular uncimformities, it is assumed that the beds were approxi- 
mately horizontal one above another when the great Appalachian 
revolution took place near the dose of Paleozoic time. This revo- 
lution was accompanied by folding, faulting, mountain building, and 


Three kinds of geologic structure are developed in the southern 
Appalachians, each one prevailing over an area corresponding to one 
of the geographic divisions. In the Cumberland Plateau and in the 
region west of it the rocks are nearly horizontal and not much altered. 
In the valley region they are steeply tilted, folded, and faulted and 
some of them are altered to slates. In the mountain district, which 
includes the Ducktown region, faults and folds are numerous, and 
slaty cleavage, schistosity, and other results of great dynamic meta- 
morphism are conspicuously developed. 

In the folded and faulted regions the major structures trend north- 
eastward. Keith* says: 

Qi^e crests of most folds continue at the same height for great distances, 
so that they present the same formation. Often adjacent folds are of nearly 
equal height and the same beds appear and reappear at the surface. 

Hayes,' describing the structure in the Cleveland quadrangle, which 
borders the Murphy quadrangle on the west, says: 

The folding is greater in thin-bedded rocks, such as shale and shaly lime- 
stone, because the thin layers were most readily bent and slipped along their 
bedding planes. Perhaps the most striking feature of the folds is the prer- 
alence of southeastward dips. In some sections across the southern portion of 
the Appalachian Valley scarcely a bed can be found which dips toward the 

The faults are mainly of the reverse type and practically all of 
them dip toward the east Some are simply ruptured folds and, as 

^Op. cit., p. 6. 

* Hayes, C. W., Cleyeland folio (No. 20), Geol. Atlas U. 8., U. S. Oeol. Survey, 1005, p. 3. 

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stated by Keith, many of them are on the northwest sides of the 

Although the folds and faults characterize both the valley region 
and the mountain area, slaty cleavage is more generally developed in 
tlie mountain area, and in many places it obscures all other structures. 
Keith * says : 

AU rocks were subjected to this process, and the final products of the meta- 
morphism of very different rocks are often indistinguishable from one another. 
* There Is a great increase of metamorphism toward the southeast, 
until the resultant schistosity becomes the most prominent of the mountain 
structures. Formations there whose original condition is unchanged are ex- 
tremely rare, and frequently the alteration has obliterated all the original 
characters of the rock. Many beds that are scarcely altered at the border of 
the vaUey can be traced southeastward through greater and greater changes 
nntU every original feature is lost. * * * 

Along these planes or zones of localized motion the original texture of the 
rock was largely destroyed by the fractures and by the growth of the new 
minerals, and in many cases this alteration extends through the entire mass 
of the rock. The extreme dCTelopment of this process is seen in the mica schists 
and mica gneisses, the original textures of which have been entirely replaced 
by the schistose structure and parallel flakes of new minerals. The planes of 
fracture and schistosity are inclined toward the southeast through most of the 
mountains, although tn certain belts * * * northwesterly dips prevail. 

♦ • * These structures ♦ ♦ • were chiefly the result of compression 
which acted most effectively in a northwest-southeast direction, at right 
angles to the general trend of the folds and of the planes of schistosity. Com- 
pression was also exerted, but to a much less extent, in a direction about at 
right angles to that of the main force. To this are due the cross folds and 
faults that atpear here and there throughout the Appalachians. 


The Ducktown district lies in the heart of the mountain country of 
the southern Appalachian province. The prevailing rocks are sandy 
schists and gray wackes with interbedded mica schists. The dominant 
series is the metamorphosed product of an association of sedimentary 
beds, including conglomerate, grits, sandstones, and shales. These 
beds grade one into another along the strike and across the bedding. 
The gritty, conglomeratic, and sandy layers are highly siliceous, frag- 
mental quartz being their most important constituent. Feldspar is 
prominent in the coarser layers and is present in nearly all the beds. 
The fine-grained layers interbedded with the sandstones and grits, 
where they are not highly metamorphosed, are dark, even-grained 
slates, but in the central and southeastern portions of the area, where 
changes are greater, they have been converted to mica and chlorite 

^ Keith, Arthar, op. dt., p. 8. 

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schisU Even these contain a very high proportion of extremely 
small quartz grains and a smaller proportion of feldspar. Quartz, 
feldspar, biotite, chlorite, and muscovite are present in all the beds, 
but the micas and chlorite predominate in the finer ones and quartz 
and feldspar are more conspicuous in the coarser beds. The most 
characteristic feature of the whole series is the lack of effective sort- 
ing of the material both as to size and composition. 

Bands of garnet or of garnet and staurolite are developed at many 
places in the schists, and in general they are more common in the 
finer beds. The garnet layers are found in stringers and bands 
scattered widely at many horizons, but the staurolitic layers are fairly 
persistent and many of them may be traced almost continuously for 
miles. They make up as much as 40 per cent of certain beds, but as a 
rule they constitute less than 10 per cent of the mass. The highly 
staurolitic beds may be traced by every gradation into beds con- 
taining staurolites only here and there. That the staurolite bands 
represent sedimentary beds which were of different composition from 
the main mass of the rock is inferred from the fact that they are 
so closely confined to the narrow parallel zones. In some of the 
rocks zones free from staurolite, perhaps 6 inches wide, alternate with 
somewhat narrower zones that are composed almost entirely of stauro- 
lites. These zones do not lie everywhere with the schistosity of the 
rock, but at some places the staurolitic bands, which are assumed to 
represent the bedding planes, lie directly across the schistosity, show- 
ing that their presence is not due to different degrees of^pressure or 
to other incidents of metamorphism. 

The schists of the Ducktown area are clearly metamorphosed sedi- 
ments. Pure staurolite contains 55.9 per cent of alumina and 15.8 
per cent of ferrous oxide. It is possible, therefore, that the staurolitic 
layers represent beds for which the material contained a considerable 
but variable proportion of clay, and unless iron was added during 
metamorphism the clay was ferruginous. Several of the staurolitic 
bands may be followed for great distances across the area. It is not 
supposed that each of these represents a separate stratigraphic hor- 
izon, for the rocks have been folded closely and eroded so that the 
same strata are repeated many times. 

Thin lenses of limestone were deposited in the great series of sedi- 
mentary rocks whose metamorphosed equivalents occupy the Duck- 
town area. These are neither extensive nor persistent and are not 
known to be exposed on the surface at any place in the district. In 
the lower levels of the East Tennessee mine the relatively pure mar- 
marized limestone is exposed at several places, and in several other 
mines masses of nearly pure white marble are inclosed in the ore. In 

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the East Tennessee mine the marmarized limestone contains layers of 
biotite and musoovite that are clearly parallel to the bedding planes 
of the rock which incloses it. The mica bands are assumed to rep- 
resent aluminous layers in the original limestones which were changed 
to micas by dynamic metamorphism. The limest(»ie is at the same 
stratigraphic horizon as the mineral deposits of the Ducktown dis- 
trict, and if it is followed on the dip it is found to grade into a rock 
composed of the gangue minerals of the ore zone with metallic sul- 
phides. In practically every mine in the district coarsely crystalline 
nutrble grades into the massive sulphide ore ; hence it is inferred that 
the mineral deposits and the associated low-grade rock composed of 
the minerals of the gangue of the ores represent limestone which has 
been replaced by ore. Voliune for volume the ore bodies carry about 
16 per cent as much lime as a relatively pure limestone, and the lower- 
grade ores with relatively small amounts of the sulphide about 24 
per cent as much. The gangue is composed mainly of actinolite, 
garnet, tremolite, pyroxene, zoisite, and other lime-bearing minerals 
which are known to have formed in a great many mining districts 
where limestone is replaced by ore. The thickness of the limestone, 
as indicated by its remnants or by the ore which is assumed to have 
replaced it, varies from less than 10 feet to more than 200 feet. At 
most places where it is thick there are indications of close folding or 
thrust faulting which have had the effect of increasing its thickness. 

The ore bodies lie in parallel groups or belts and not all the de- 
posits of a single belt are connected by ore. No limestone is exposed 
in the intervals between the deposits ; consequently it is inferred that 
the limestone lenses were not continuous. Although there are several 
such disconnected belts of ore bodies it is not supposed that the lime- 
stone lenses which they replaced were deposited at an equal number 
of horizons in the schist. The horizon of the replaced limestone is 
approximately that of the staurolitic beds that occur in the mineral- 
ized area. These beds are not found in the walls of every ore body, 
but they outcrop locally along or near every important lode. They 
are present on both sides of the Isabella-Eureka lode and in or along 
the continuation of the beds that form the walls of the Polk County, 
Old Tennessee-Cherokee, Burra Burra, London, East Tennessee, and 
Mobile lodes. The outcrops of the staurolite beds and limestone have 
probably been repeated by close folding and erosion. 

The sedimentary series contains here and there small veinlets of 
quartz-feldspar pegmatite and short, narrow lenses and layers of a 
rock composed of quartz, feldspar, hornblende, garnet, and zoisite. 
It is intruded by gabbro dikes, which generally follow the bedding 
of the schista 

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The age of the sedimentary series which occupies the Ducktown 
region can not be definitely stated, but there are many reasons for 
correlating this series with the Great Smoky formation described by 
Keith and others as occurring in the quadrangles surrounding the 
Ducktown district. Certain phases of the Carolina gneiss, however, 
are closely similar to the most intensely metamorphosed phases of 
the Great Smoky formation. A granite gneiss is known to outcrop 
in the Dalton quadrangle, southwest of the Ducktown district, and 
it is possible that this or equivalent formations may extend eastward 
and northeastward into the Ducktown region. Although the great 
mass of lithologic and structural evidence seems to admit the corre- 
lation of the schists at Ducktown with the Great Smoky formation, 
there is a possibility that the Carolina gneiss may also be represented 
in the district. The correlation can not be conclusive until more 
detailed mapping has* been done in the Dalton quadrangle, southwest 
of the Ducktown district. 

Gabbro is intruded in the schists at several places. The largest 
body is a relatively narrow dike about 4 miles long, which extends 
from a point on Fightingtown Creek, half a mile southeast of the 
Mobile mine, northeastward to a point half a mile east of Coletown. 
A small mass of gabbro occurs near the wagon road between 
the Boyd mine and Ducktown. The gabbro is a dark granular rock 
not so highly schistose as the inclosing beds, and is later than the 
more profound dynamic metamorphism which converted the sedi- 
mentary rocks into schist. 


In late Paleozoic time the great series of sedimentary rocks was 
subjected to enormous lateral pressures. These pressures, which 
may be considered as forces operating tangentially to the earth^s 
crust, were not all equal and those which were greatest operated in 
northwest and southeast directions. As results of these differences 
the rocks were shortened in the direction of greatest pressures and 
thrown in many closely spaced parallel folds. Nearly all these, as 
already stated, trend northeastward.* The tops of many of the 
folds or crests of the anticlines are formed of the same beds and are 
at approximately the same elevations. The same bed, exposed by 
erosion, will consequently outcrop as a number of closely spaced 
parallel belts, some of which are traceable for great distances. In 
every quadrangle surrounding the Ducktown area the reduplication 
of beds is a most conspicuous geologic feature. Not all the beds are 
everywhere parallel; some of them outcrop as sharp S -shaped folds, 

^ Keith, Arthur, Nantahala folio (No. 143), Oeol. Atlas U. S., U. 8. Oeol. Survey, 1907. 

Digitized by 



but at many places the beds continue at either end of the S in a 
northeast or southwest direction parallel to the general strike. Re- 
verse faulting accompanied the folding of the rocks. 


The deformation of the beds which resulted in close folding was 
accompanied also by mashing, recrystallization, and the develop- 
ment of slaty cleavage and schistosity. The small quartz grains in 
the sediments were revolved so that the longer axes were oriented 
parallel to the direction of least pressure. Muscovite, biotite, 
chlorite, and other flat minerals were crystallized and these were 
oriented so that the longer dimensions were likewise in the direction 
of least pressure and parallel to the longer axes of quartz fragments. 
As a result of these processes a high degree of schistosity was devel- 
oped in the rocks, especially in the finer-grained members and in 
those that contained considerable material from which it was possi- 
ble to form platy minerals like the micas and chlorite. 



The deposits are included in an area 6 miles long and 4 miles wide, 
and all are located on the dissected peneplain which occupies the cen- 
tral portion of the Ducktown Basin. The outcrops are composed of 
iron oxides and quartz and contrast strongly with the country rock. 
All the lodes have a general northeastward strike. South of the Cul- 
chote mine, which is near the center of the productive area, they strike 
more nearly north than east; north of the Culchote they strike 
more nearly east than north. In general the lodes dip southeast, but 
some dip northwest. The deepest development underground is about 
800 feet below the surface. The distribution of the lodes is shown 
in figure 25. 

In the main the deposits are roughly tabular. Some of them are 
lens shaped and most of them are at places curved. All are included 
in metamorphosed sedimentary rocks and, except where faulting or 
close folding is apparent, the beds are parallel to the contacts of ore 
and country rock. 

The primary ore consists of pyrrhotite, pyrite, chalcopyrite, zinc 
blende, bomite, specularite, magnetite, actinolite, calcite, tremolite, 
quartz, pjrroxene, garnet, zoisite, chlorite, micas, graphite, titanite, 
and feldspars. The minerals are generally intergrown and of con- 
temporaneous age. Essentially the same minerals are found in all 
the deposits, but they appear in varying proportions at different 
places in the lodes. Where the content of copper is above 1.5 per 

94174'— Bull. 470—11 11 

Digitized by 



cent, or where sulphur is high, the material is ore, but where the pro- 
portion of actinolite and other lime silicates is greater and the sul- 
phides less abundant the material, though containing copper and 


CAST Te*lti£SSE£yJ^ 

BOiftfA 3U»n*^ 


00Y0 4^ 









GraywBcke and mica schist* 
Ore zone 


Staurolific beds 
4000 Feet 

FiGUBB 25. — Sketch map showing the location of the principal ore deposits In the pro- 
ducing portion of the Ducktown district. The arrows indicate dips of lodes. 

sulphur, is unworkable. Along the strike and down the dip the ore 
grades into this lime-silicate rock, and in some places it grades into 
marmarized limestone. The ore zones may be considered therefore as 

Digitized by 




tabular bodies composed of ore, of lime-silicate rock, and of marble. 
As thus defined these zones vary from a few feet to nearly 200 feet 
in width and average probably between 50 and 75 feet. The amount 
of ore is about equal to that of the lime-silicate rock and marble. At 
some places the ore, the lime-silicate rock, and the limestones have schis- 
tosity or banding which is parallel to the boundaries of the ore zone, 
and wherever bedding planes have been made out in the marble and 
in the lime-silicate rocks these are likewise parallel, to the boundaries 







' 7 VW 










'I If/ f /' '// 

200Feet /^6Thl£V£l 

— ' 7 

Schist Ore zone 


Oossaa Chalcociteor* 
Figure 26. — Cross section of the Mary mine, chamber 3 S. 

of the ore zone and country rock. Some of the layers of sandy schist 
included in the ore zone are believed to represent beds that were de- 
posited with the limestones. 


The ore minerals are not arranged in layers or crusts one upon an- 
other, like the minerals deposited from solutions in an open cavity, 
but are intergrown and are assumed to have formed at the same time. 

Digitized by 



At some places the silicates inclose the sulphides, at others the sul- 
phides inclose the silicates, and at still others the two are intimately 
intergrown so that neither set of minerals may be said to inclose the 

other. The ox- 
ides, magnetite and 
specular hematite, 
are not abundant, 
but both have been 
recognized, and 
where they are de- 
veloped they are 
intergrown with 
the sulphides and 
with the lime sili- 
cates. Where the 
purer limestones 
are recrystallized 
into marble the 
bedding is not ap- 
parent, but in the 
aluminous phases 
it is clearly shown. 
Veinlets of pyr- 
rhotite and chal- 
copyrite cut the 
hornblende and 
zoisite in some of 
the ore and fill 
cracks along the 
cleavage of the 
silicates. At 
many places the 
sandy schists near 
the ore zone are 
heavily impreg- 
nated with iron 
and copper sul- 
phides, but this 
material is gener- 
ally not workable. 
Along fault zones, 
where drag of ore and schist have been replaced and impregnated, 
workable ore is locally developed. 

Figure 27. — ^Plan of 20-fathom level, East Tennessee mine. 
The solid lines Indicate mine workings aod drill holes. The 
arrows show the dip of the ore zones. 

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In the Mary mine, near the Baxter shaft, the ore zone is clearly 
folded. This fold, which is shown in figure 26, is exposed on several 
levels. The thickening of the ore on the crest of the anticline is con- 
spicuous in this section, but not all sections of anticlines show this 
feature. Figure 27 is a plan of the 20- fathom level of the East Ten- 
nessee mina At the Thomas shaft the ore zone bends, making a 
horseshoe curve, with ore extending from the center of the curve 
southwestward at least 125 feet. On the inner side of this curve, as 
elsewhere, the schistosity conforms with the ore body. This contact 
is very well defined and the walls are smooth, suggesting that move- 
ment has taken place on both flanks of the curved ore body. The 
walls dip to the southeast at high angles, except at the sharp curve, 
where they dip about 85® SW. This curved plane and the bent ore 
body are exposed on several levels. 

Other faults cut the ore bodies, but they follow the strike ap- 
proximately, and as horizon markers are not always available the po- 
sitions of the greater number of these faults can not be accurately 



(1) The conclusion that the ore bodies are replacement deposits 
is supported by several lines of evidence. All the lodes are inclosed 
in sedimentary rocks and, except where faulting has taken place, 
the deposits are oriented parallel to the bedding. Along the 
horizons of the replaced rock there are aluminous beds, in places 
staurolitic, which are probably metamorphosed products of strata of 
a composition unlike that of the associated beds. The staurolitic 
layers are confined to certain beds, and where they are present they 
serve as reliable markers of the bedding. These beds parallel some 
of the lodes for great distances. 

At some places the exposures of the ore zone are over 200 feet wide. 
Although fissure veins as wide as these are not unknown, they are 
in the main, if not altogether, replacement veins or fractured zones, 
not clean-cut filling deposits such as those which occupy wide spaces. 
The association of ore and gangue minerals in the Ducktown lodes 
is characteristic of deposition at considerable depth and under pres- 
sure. It seems improbable that spaces of great size would remain 
open at the depths at which these minerals are assumed to have 

The internal structural features of fissure fillings are lacking in 
the Ducktown lodes. Fissure fillings as a rule show well-defined 
comb structure here and there, with open spaces or druses lined with 
banded crusts. Such features are nowhere developed in the Duck- 
town deposits except in the small calcite or quartz seams and vein- 
lets, which cross the ore bodies and which are clearly later than the 


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ore. Locally crystals of amphiboles, garnet, and other heavy silicates 
project into open spaces in the lodes, but these minerals are not crusti- 
fied, and in all cases observed in the course of this investigation 
calcite is intergrown with the projecting heavy silicates. It is 
believed that in all such relations the cavities represent spaces 
from which calcite or some other readily soluble mineral has been 

There is little evidence of premineral Assuring along the walls of 
the lodes. The contact between the ore and mica schist is at many 
places tightly frozen. At some places slickensided planes cut the 
ore and the country rock, but these planes do not limit the ore bodies 
and are clearly of later age than the ores. Here and there veinlike 
deposits of ore make off from the main ore zone, but these are so 
small that they are not mined. They are probably calcite veins 
formed during the intense metamorphism of the limestone and asso- 
ciated rocks and subsequently replaced by ore. The minute fractures 
filled with chalcopyrite, which here and there cut the ore and the 
siliceous wall rock, are believed to have been formed by a transfer of 
material after the primary ores had been deposited and shattered 
by movement. 

(2) The ores replace limestone. AH the abundant gangue min- 
erals except quartz contain considerable lime. These include calcite, 
actinolite, tremolite, pyroxene, garnet, and zoisite. The lime sili- 
cates are known to be developed at many places and in widely sepa- 
rated districts by replacement of limestone. These minerals are 
intimately intergrown with the sulphides and are of contempora- 
neous age. Almost every piece of ore which one may examine will 
be found to contain one or more of the lime silicates. They consti- 
tute a considerable proportion of the great masses of ore and even 
the small pieces of ore which at first appear to be composed solely 
of iron sulphides are found on close examination to contain them. 
The ore mined from the Burra Burra mine for a period of 12 months 
averaged 6.32 per cent of CaO; that mined from the London mine 
for the same period averaged 6.82 per cent; and that from the Polk 
CJounty mine 6.30 per cent. 

As already stated, the lodes are everywhere inclosed in graywacke 
or in mica schist. Near the lodes this rock generally carries sulphides, 
but the mineral associations of schist and of ore zone are distinctly 
different. At many places the contact between the ore zone and the 
schist is gradational, but the zone of gradation is in general not more 
than a few inches wide. There are relatively few places where the 
contact zone is more than a foot wide. If the ore had been depos- 
ited along a crushed zone, replacing the schist, the boundaries would 
presumably be less sharply defined. Along the strike, however, the 
ore grades here into a rock composed almost entirely of actinolite. 

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tremolite, and calcite; there into one composed essentially of actino- 
lite or of calcite. These masses of actinolite or of actinolite and 
tremolite in the Polk County, Mary, and other mines constitute 
about half of the ore zone. In some of these mines the ore may be 
regarded as irregular masses of sulphides spaced apparently hap- 
hazard in a relatively narrow zone of actinolite rock, which is 
inclosed between walls of graywacke. The actinolitic phase of the 
ore zone carries about 12 per cent of calcium oxide, but the average 
of several analyses of the country rock shows less than 1 per cent 
of lime. 

At certain places in nearly all the mines masses of marmarized 
limestone are inclosed in the ore or in tremolite or actinolitic rock. 
These masses have not been found outside of the ore zone. Generally 
they contain a few shreds of the calcareous amiphiboles, of pyroxene, 
or of garnet and a few minute grains of pyrite or of chalcopyrite. 
Inr all the mines except the East Tennessee these masses of limestone 
are small and may easily escape the attention of one who is not 
looking for them. In the East Tennessee mine, however, masses of 
marmarized limestone for 20 feet or more along the strike occupy 
almost the entire width of the ore zone. On the ninth level of this 
mine the bedding planes of the limestone are clearly shown. They 
are parallel to the walls of the limestone lens and to the bedding 
planes of the inclosing quartz-biotite schist. 

As the East Tennessee lode is at the same stratigraphic horizon as 
the London and Burra Burra lodes, and as it is clearly a replacement 
of limestone, it is rational to suppose that the rock replaced in the 
London and Burra Burra is also limestone. As already stated, the 
same minerals are present in all the ore bodies developed in the dis- 
trict. The ore bodies differ in chemical composition because these 
minerals are present in different proportions in the several lodes. 
On every large mine dump in the district one may obtain a suite of 
specimens showing all gradations from a marmarized limestone, 
composed almost entirely of calcite, to the typical sulphide ore. 

(3) The limestones were probably replaced by magmatic waters. 
The minerals of the ore zone are those typically associated with ores 
which have been deposited by the replacement of limestone along or 
near intrusive masses. With the exception of quartz and calcite, the 
gangue minerals, abundant in the ore zone, are all lime silicates. 
They include actinolite, tremolite, pyroxene, garnet, and zoisite, all 
of which are characteristic of igneous metamorphism. The ore 
minerals include pyrrhotite, pyrite, chalcopyrite, zinc blende, galena, 
magnetite, and specularite. These are intergrown with calcite and 
with the heavy silicates and must have formed simultaneously with 

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It has been shown that at many widely separated places in North 
America ^ similar associations of ore and gangue minerals have been 
formed as a result of the metamorphism of limestone by hot solutions 
from igneous bodies. The mineral associations in these deposits are 
so nearly constant that they appear to have a genetic significance. 
It is assumed, therefore, that the deposits of Ducktown ifv ere formed 
by similar agencies, although the source of the solutions is not known. 
The schists near the ores are intruded by gabbro and contain small 
bodies of pegmatite, and either of these rocks may be evidence of the 
same igneous agencies that deposited the ores. When it is recalled, 
however, that other and larger masses of intruded igneous rock are 
present in the southern Appalachian region at places more remote 
from the Ducktown district, the correlation of the deposits with the 
intrusion of any particular igneous body is obviously a matter of 

(4) The forms of the ore bodies and their relations to other beds 
show that the rock which the ores replaced, or the ore bodies them- 
selves, have been involved in all of the deformation by dynamic 
metamorphism to which the country rock has been subjected. The 
major portion of the dynamic metamorphism, resulting in the devel- 
opment of slaty cleavage and close folding of the beds, may have 
taken place before the mineralization, but some deformation has 
occurred since the ores were deposited. The gangue minerals which 
are included in the sulphides are generally broken and crushed, and 
in some thin sections of the ore the pyrrhotite shows minute crink- 
ling of closely spaced planes. Pyroxene and zoisite crystals are 
bent and twisted. At many places the ore appears brecciated, and 
small balls consisting predominantly of actinolite, garnet, and 
quartz with a subordinate amount of sulphides are surrounded by 
heavy sulphide ore containing numerous broken fragments of horn- 
blende. In the No. 20 mine some of these balls are elongated 
ellipsoids. At some places the minerals of the gangue are oriented 
in parallel layers, like the minerals of a schist, but in general the 
gangue of the ores is not schistose. Becrystallization, following 
deformation, may have obscured certain metamorphic structures. 
Little is known regarding the behavior of metallic ores in differ- 
ential stresses under heavy load, and the data are insufficient to 
warrant a statement regarding the degree of the deformation of the 
ores or the depth at which they were deformed. 

^ Lindgren, Waldemar, Copper deposits of the Clifton-Morencl district, Arizona : Prof. 
Paper U. S. Geol. Surrey No. 43, 1905, p. 218. Kemp, J. F., Ore deposits at the 
contacts of intnisive rocks and limestone and their signiflcance as regards the general 
formation of veins : Econ. Geology, vol. 2, 1907, p. 1. 

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It has been shown that the lodes are replacements of limestone 
lenses. Throughout this portion of the mountainous area of south- 
eastern Tennessee the outcrops of beds are repeated again and again 
by close folding, a reverse faulting, and subsequent erosion. It would 
be a natural inference that the lenses which the several lodes replace 
were all formed at the same stratigraphic horizon, and that the ore 
zone was likewise repeated by close folding. The close association 
of staurolite with the ore zone and its common occurrence on the 
hanging-wall side would seem to be in harmony with this interpreta- 
tion. In certain places in the area, however, the staurolite bed is lack- 
ing. The evidence that all the ore bodies are at the same strati- 
graphic horizon is therefore incomplete, and the correlation of the 
several deposits can not be made on the basis of the data at hand. 
Where the rocks are closely folded and much faulted, as they are 
in the Ducktown district, a number of interpretations are possible, 
and because continuous separable beds are rare, it is not always 
possible to show which one is true. It is hoped, however, that cer- 
tain working hypotheses may be suggested when all the data shall 
have been assimilated. 


General statement. — ^The Ducktown lodes are composed of three 
kinds of ore. The outcrops consist of hydrous iron oxides with 
smaller proportions of other minerals, chiefly kaolin and quartz. 
This ore extends from the surface downward to a maximum depth of 
about 100 feet. Below the iron ore there is generally a few feet of 
chalcocite ore, which in most of the deposits lies like a floor below the 
gossan iron ore. Below the chalcocite zone is the yellow sulphide ore 
which has already been described. This ore extends downward as 
far as exploration has gone and is assumed to be the primary ore from 
which the chalcocite zone and the gossan have been derived. In all 
the deposits now mined the chalcocite was almost completely ex- 
hausted years ago and a large portion of the gossan ores has been 
shipped to iron furnaces. The opportunities for studying these ores 
are now meager. The workings in black ore are accessible in some of 
the mines, but even where the ores have not been removed extensive 
changes have doubtless taken place as a result of leaching after the 
ground-water level was depressed by mining and pumping in levels 

Distribution and character of the iron ore. — ^The deposits of gossan 
ore vary in width from a few feet, as shown in the narrow openings 
along the Cherokee lode, to 250 feet in the Isabella and Eureka pits. 

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Few of them extend downward from the surface more than 100 feet. 
The greatest depths are below the hilltops, and where the lodes are 
crossed by running streams the gossan ores are thin or lacking. 

The iron ore is porous and earthy. It carries from 40 to 50 per 
cent of iron and on account of its low content of phosphorus it is 
especially desirable for mixing with lower grade high-phosphorus 
ores to bring the mixture within the Bessemer limit. Silica and 
alumina together are generally less than 12 per cent, although in some 
of the ores they are as high as 17 per cent. Copper varies from 0.3 
to 0.7 per cent. 

Hydrous iron oxides are the most abundant minerals. Silica is 
present in varying amoimts. Some of it is quartz residual from the 
primary ore, but a red siliceous mineral resembling jasper was noted 

1000 Foet 

Gossan iron ore Horizon of Lovs^-^rade iron and 
chalcocile copper sulphides 
FiGURB 28. — Side elevation of a portion of the Oid Tennessee-Cherokee lode, looking N. 

56* W. 

in several of the deposits. Some of this is an intimate mixture of 
hydrous silica and iron oxide which has formed presumably by the 
solution and precipitation of silica during weathering of the de- 
posits. A small amount of kaolin is generally present. It is de- 
veloped by reactions of sulphate water on the aluminous minerals of 
the ore and wall rock. Cuprite has been noted in the oxidized ores 
and it is probably the principal copper mineral. Native copper has 
been reported. A small amount of sulphur, less than 1 per cent, is 
present. It occurs as native sulphur, in pyrite, and in sulphates. 

Distribution and composition of the zone of secondary copper ore.— 
Below the gossan iron ores is a zone of dark, rich copper ores, consist- 
ing of chalcocite and other copper minerals in a gangue of sulphates, 
quartz, and deccmiposed silicates. Under the higher portions of the 
outcrops of the lodes the top of this zone is about 100 feet below the 
surface, but the depth decreases down the slopes and where the lodes 
are crossed by running streams the secondary copper ores are exposed 
at the surface. The upper limit of the chalcocite zone follows the 
level of ground water, which, in turn, follows the contour of the coun- 
try but is less accentuated. Figure 28 is a longitudinal projection 


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along the Old Tennessee-Cherokee lode based on data supplied by the 
Virginia Iron, Coal & Coke Co., which mined the gossan ores of this 
deposit. The heavy black line has been added to indicate the horizon 
and approximately the extent of the secondary ores. Below the chal- 
cocite zone is the lower-grade primary ore. 

The rich secondary copper ore is a mixture of the primary minerals 
and minerals that have been deposited by sulphate waters since the 
deposits were exposed to weathering. Not much of the secondary 
ore was available for study in the course of this investigation, and the 
list of minerals and the facts ascertained as to their occurrence and 
relations are obviously incomplete and unsatisfactory. 

The following minerals have been recognized by diflFerent writers : 
Alisonite, allophane, alums, argentite, azurite, bomite, chalcanthite, 
chalcedony, chalcocite, chalcopyrite, chrysocolla, covellite> cuprite, 
ducktownite(?), gypsum, harrisite(?), iron sulphate, jasper, kaolin, 
limonite, malachite, marcasite, melaconite, native copper, rahtite(?), 
sulphur, talc, turgite. The secondary ore contains also pyrite, chal- 
copyrite, pyrrhotite, zinc blende, and galena, with actinolite, quartz, 
tremolite, garnet, and other gangue minerals of the primary ore. 

Four analyses of the mine waters made by Dr. R. C. Wells are 
stated below. 

No. 1 represents a sample from the East Tennessee mine taken on 
the 30-fathom level. The water is flowing in a small stream over the 
primary sulphide ore and is exposed freely to the atmosphere. In 
this water only does zinc exceed copper. 

Analysis No. 2 represents a sample taken from the Burra Burra 
mine in the first level below the black copper workings. This water 
seeps through the workings in the chalcocite zone along a fissure 
which extends downward into the pyrrhotite ore and was caught 
frcwfi a stream dripping from the roof. The high content of copper, 
zinc, and ferrous iron is noteworthy. Although the sample was taken 
in the open air, none of the iron is oxidized to the ferric state. This is 
remarkable, because no precautions were taken to prevent the oxida- 
tion of this sample. 

Samples 8 and 4 were taken from the Callaway shaft. Sample 8 
was taken from the top of the water column in this shaft and sample 
4 was taken 87 feet below. A special device was used to filter sample 
4 under the 37 feet of water pressure. 

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Analyses of mine waters from DucJetown district 





Addlty as HiSOia 












































Sio...^ ..r 


Ai. :..:::::::::::::::: 




















SO* ::: : : 




a Determined after shipping, when partial hydrolysis had occurred. 

Chalcocitization. — ^Weathering and related processes operating on 
an ore composed of iron and copper sulphides generally result in the 
enrichment of a certain zone. As a rule, the top of this zone is near 
the water level and it extends downward for varying distances below 
the water level. As shown by the analyses, the waters are sulphate 
solutions, and in the zone above the water level, where air is admitted, 
acid or ferric sulphates predominate. In such solutions copper is 
readily dissolved. Below the water table the acid reacts with sul- 
phides that precipitate copper sulphide from sulphate solutions. 
From the sulphides hydrogen sulphide is formed. The sulphuric 
acid is used up also by reactions with gangue minerals, some of which 
result in the production of calcium sulphate, alkali sulphates, and 
other inert salts. The solutions below the water level are consequently 
less acid and probably do not dissolve copper. It is noteworthy that 
the solution taken 37 feet below the water level in the Callaway mine 
contains less than half the free acid stated in the analyses of the 
sample taken at the water level. 

The secondary zone in the Ducktown district is less extensive verti- 
cally than most chalcocite zones elsewhere. The lodes are compara- 
tively impervious to downward circulation, and it is believed that the 
reactions were brought near to completion before the descending 
oxidized solutions had moved downward great distances. It is 
thought also that the reactions precipitating copper sulphide take 
place more rapidly with pyrrhotite than with pyrite or chalcopyrite. 
Experiments planned to show the rate of solution of different min- 
erals in acid sulphate waters and the rate at which hydrogen sulphide 
is liberated by these minerals in dilute acid solutions are being made 
by Dr. R. C. Wells, of the Geological Survey. It is hoped that 
quantitative data may soon be available for the discussion of these 

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The following list includes the principal publications on copper by 
the United States Geological Survey or by members of its staflF. In 
addition to the publications cited below, certain of the geologic folios 
listed in the " Introduction " contain discussions of the copper re- 
sources of the districts of which they treat. 

The Government publications, except those to which a price is 
affixed, can be obtained free by applying to the Director, U. S. Greo- 
logical Survey, Washington, D. C. The priced publications may be 
purchased from the Superintendent of Documents, Government 
Printing Office, Washington, D. C. The one marked " Exhausted " 
is not available for distribution, but may be seen at the larger libra- 
ries of the country. 

Bain. H. F., and Ulbich, E. O. The copper deposits of Missouri. In Bulle- 
tin 260, pp. 233-235. 1905. 40c. 

Ball, S. H. Copper deposits of the Hartville uplift, Wyoming. In Bulletin 
315, pp. 93^107. 1907. 

Bancroft, Howlano. Reconnaissance of the ore deposits in northern Yuma 
Ck)unty, Ariz. Bulletin No. 451. 

BotJTWELL, J. M. Ore deposits of Bingliam, Utah. In Bulletin 213, pp. 105- 
122. 1903. 25c. 

Economic geology of the Bingham mining district, Utah. Profes- 
sional Paper 3a 413 pp. 1905. 

Ore deposits of Bingham, Utah. In Bulletin 260, pp. 236-241. 

1905. 40c 

BuTLEB, B. S. Copper. In Mineral Resources U. S. for 1909, pt. 1, pp. 151- 
180. 1911.* 

Ck>LLiEB, A. J. Ore deposits of the St Joe River basin, Idaho. In Bulletin 
285, pp. 129-139. 1906. 

DiLLEB, J. S. Ck>pper deposits of the Redding region, California. In Bul- 
letin 213, pp. 123-132. 1903. 25c. 

Mining and mineral resources in the Redding district in 1903. In 

Bulletin 225, pp. 169-179. 1904. 35c. 

Emhons, S. F. Geological distribution of the useful metals in the United 
States— Copper. Trans. Am. Inst. MIn. Eng., vol. 22, p. 73. 1894. 

Economic geology of the Butte (copper) district, Montana. Geologic 

Atlas U. S., folio No. 38. 1897. 

^See also Qold, silver, copper, lead, and zinc (mine prodaction) in Western, Central, 
and Eastern States, by various authors. In Mineral Resources U. S. for 1909, pt 1, 
pp. 221-647. 1911. 


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Emmons, S. F. Copper in the red beds of the Colorado Plateau region. In 
Bulletin 200, pp. 221-232. 1006. 40c. 

The Cactus copper mine, Utah. In Bulletin 260, pp. 242-24& 1905. 


Emmons, W. H. The Cashin mine, Montrose County, Colo. In Bulletin 285, 
4)p. 125-128. 1906. 

Some ore deposits of Maine and at the Milan mine. New Hampshire. 

Bulletin 432. 62 pp. 1910. 

Gale, H. S. Geology of the copper deposits near Montpelier, Bear Lake 
County, Idaho. In Bulletin 430, pp. 112-121. 1910. 

Gbaton, L. C. Copper. In Mineral Resources U. S. for 1906, pp. 373--438. 
1907. 60c. 

Copper. In Mineral Resources U. S. for 1907, pp. 671-644. 1908. $1. 

The occurrence of copper in Shasta County, Cal. In Bulletin 430, 

pp. 71-111. 1910. 

Howe, H. M. Copper smiting. Bulletin 26. 107 pp. 1885. Exhausted. 

lEviNG, R. D. The copper-bearing rocks of Lake Superior. Monograph V- 
464 pp. 1883. $1.86. 

LiNDGBEN, Waldemab. The copper deposits of the " Seven Devils,'* Idaho. 
In Min. and Sci. Press, vol. 78, p. 126. 1899. 

The copper deposits of the Seven Devils. In Twentieth Ann. Rept., 

pt 3. pp. 249-263. 1900. 

Copper deposits of Snake River and Powder River, Oregon. In 

Twenty-second Ann. Rept., pt 2, pp. 551-776. 1901. 

Copper deposits at Clifton, Ariz. In Bulletin 213, pp. 133-140. 1908. 


Copper deposits of Clifton-Morenci district, Arizona. Professional 

Paper 43. 376 pp. 1905. 

Notes on copper deposits in Chaffee, Fremont, and Jefferson counties, 

Colo. In Bulletin 340, pp. 157-174. 1908. 

Resources of the United States in gold, silver, copper, lead, and zinc. 

In Bulletin 394, pp. 114-166. 1909. 

LiNDGBEN, W., and Gbaton, L. C. A reconnaissance of the mineral deposits of 
New Mexico. In Bulletin 285. pp. 74-^. 1906. 80c. 

LiNDGBEN, W., Gbaton, L. C, and Gobdon, C. H. The ore deposits of New 
Mexico. Professional Paper 68. 361 pp. 1910. 

Phalen, W. C. Copper deposits near Luray, Va. In Bulletin 285, pp. 140- 
143. 1906. 

Ransome, F. L. Copper deposits of Bisbee, Ariz. In Bulletin 213, pp. 149- 
157. 1903. 25c. 

The Globe copper district, Arizona. Professional Paper 12. 168 pp. 

1904. 70c. 

Geology and ore deposits of the Bisbee quadrangle, Arizona. Pro- 
fessional Paper 21. 168 pp. 1904. 

The Terington copper district, Nevada. In Bulletin 380, pp. 99-119. 


Geology at Globe, Ariz. In Min. and Sci. Press, vol. 100, No. 7, pp. 

256-267. 1910. 

Ransome, F. L., and Calkins, F. C. The geology and ore deposits of the 
Coeur d'Alene district, Idaho. Professional Paper 62. 1908. 86c. 

Sfenceb, a. C Mineral resources of the Encampment copper region, Wyo- 
ming. In Bulletin 213, pp. 168-162. 1903. 26c. 

Reconnaissance examination of the copper deposits at Pearl, Colo. In 

Bulletin 213, pp. 163-169. 1908. 25c 

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Spenceb, a. C. Copper deposits of the Encampment district, Wyoming. Pro- 
fessional Paper 25. 107 pp. 1904. 15c. 

Stosb, G. W. The copper deposits of South Mountain in southern PeDusyl- 
vania. In Bulletin 480, pp. 122-131. 1910. 

Vabious attthobs. Gold, silver, copper, lead, and zinc (mine production) in 
Western, Central, and Eastern States. In Mineral Resources U. S. for 1909, 
pt, 1, pp. 221-647. 1911. 

Vaitghan, T. W. The copper mines of Santa Clara Province, Cuba. In Eng. 
and Min. Jour., toL 72, pp. 814-816. 1901. 

Watson, T. L. Notes on the Seminole copper deposits of Georgia. In Bul- 
letin 225, pp. 182-186. 36c. 

Weed, W. H. Types of copper deposits in the southern United States. In 
Trans. Am. Inst. Min. Eng., vol. 30, pp. 449-604. 1901. 

Copper mines of Las Vegas, Chihuahua, Mexico. In Trans. Am. 

Inst. Min. Eng., vol. 32, pp. 402-404. 1902. 

Copper deposits near Jimenez, Chihuahua, Mexico. In Trans. Am. 

Inst. Min. Eng., vol. 32. pp. 404-406. 1902. 

Copper deposits of Cananea, Sonora, Mexico. In Trans. Am. Inst 

Min. Eng., vol. 32, pp. 428-436. 1902. 

Oredeposits at Butte, Mont. In BuUetln 213, pp. 170-180. 1903. 26c. 

Copper deposits of the Appalachian States. In Bulletin 213, pp. 

181-186. 1903. 26c. 

Copper deposits in Georgia. In Bulletin 225, pp. 180-181. 1904. 35c. 

The Grlggstown, N. J,, copper deposit. In Bulletin 225, pp. 187-189. 

1904. 35c 

Notes on the copper mines of Vermont. In Bulletin 225, pp. 190-199. 

1904. 35c. 

The copper production of the United States. In Bulletin 260, pp. 

211-216. 1905. 40c. 

The copper deposits of eastern United States. In Bulletin 260, pp. 

217-220. 1906. 40c. 

The copper mines of the United States in 1905. In Bulletin 286, pp. 

93-124. 1906. 

Copper deposits of the Appalachian States. Bulletin 455. 166 pp. 


Weed, W. H., and Pibsson, L. V. Geology of the Castle Mountain mining 
district, Montana. Bulletin 139. 164 pp. 1896. 15c. 

Weeks, F. B., and Heikes, V. C. Notes on the Fort Hall mining district, 
Idaho. In Bulletin 340, pp. 176-183. 1908. 

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Lead and Zinc. 




The purpose of this paper is to give a short summaiy of incidental 
notes on the mineral deposits, mainly lead and copper, in the Bear 
River Range of Idaho and Utah, concerning which there is appar- 
ently little on record. The notes were taken by members of the 
United States Geological Survey in connection with a reconnaissance 
examination of the portion of the range lying partly in and border- 
ing on the phosphate reserve as originally constituted by the with- 
drawals made by the Secretary of the Interior in December, 1908, 
and December, 1909. The Bear River Range extends in a north- 
south direction from latitude 40^ 15' to 42^ 45' and separates Cache 
Valley on the west from Bear Lake Valley on the east. Its length is 
approximately 120 nules and its average width 10 to 15 miles. The 
location of the range and the localities described are indicated in 
figure 29. 

generaij description of mineralized area. 

The mineral deposits of this area have been known and prospected 
for 15 or 20 years and the prospect pits are so numerous that only a 
small part of them were visited. They are scattered over the east 
side of the range from the vicinity of WoodruflF, Utah, north to Soda 
Springs, Idaho. The lead ores consist of galena with small amounts 
of cerusite and wulfenite in a gangue of ironnstained calcite and 
dolomite and are found at Swan Creek, Utah, and near St. Charles 
and Paris, Idaho. They appear to be tabular replacement deposits 
in limestone, more or less parallel to the bedding and cut and limited 
by fissures. 

94174**— Bull. 470—11 ^12 177 

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The copper ores consist mainly of the carbonates, azurifce and 
malachite, in quartz veins and locally of the sulpharsenite and sulph- 
antimonite, tennantite and tetrahedrite, in a brecciated quartz and 

Tjqjjkk 29.— Map showing retetlon of mining prospeots to Bear River Range and cnrerthnist. The marglD 
of the overthrust block Is indicated by the heavy broken Une. 

jasper gangue. Both modes of occurrence are found in quartzites 
of probable Cambrian age. Igneous rocks are not associated with 
either the lead or the copper ores. 

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Shipments of ore have been made from two localities, the Boulder 
Bonanza^Humming Bird group and the Blackstone mine, west of 
Paris and St. CharleS; Idaho, respectively. The shipments from the 
former group are reported to have been somewhat less than 100 tons, 
partly lead and partly copper ore, while that of the latter comprise 
about 800 tons of high-grade concentrates. 



The geologic structure of the range as a whole has not been worked 
out, but the data collected by the geologists of the Hayden Survey* 
lead to the inference that it is synclinal, the youngest rocks occupy- 
ing the center of the trough. The eastern flank is known to consist 
of a great overthrust block of folded and broken Middle Cambrian to 
MiasisHJppian limestones and quartzites. This block rests on rocks 
in part of Triassic age, and the magnitude of the thrust is indicated 
by the fact that it is traceable for a distance of about 100 miles, from 
the vicinity of Woodruff, Utah, to a point north of Soda Springs, 
Idaho (see fig. 29), and is practicaUy coextensive with the range^tself . 
The direction of movement is from west to east and the maximum 
apparent displacement about 10 miles. The dip of the fault plane is 
low, not over 10° on an average, although locaUy it may exceed that 
amount. In general the fault is not expressed in the topography, 
but west of Lanark, Idaho, a retreating scarp bears evidence of the 
efficiency of erosion. The strata included on the eastern margin of 
the thrust block form an anticline paralleled on the west by a syn- 
cline in the vicinity of St. Charles and Paris, Idaho, and the mineral 
deposits which have been visited in that neighborhood are located on 
the intervening monocline. The dips in this fold are uniformly 
toward the west and range from 20° to 30°. 


The main mass of the Bear Biver Range is made up of Paleozoic 
sediments ranging from Middle Cambrian to Mississippian in age. 
Rocks of probable Triassic age underlie the overthrust block on the 
east and minor amounts of Tertiary lake beds are foimd in patches 
on the summits and in a terrace-like fringe about the lower hills. No 
igneous rocks are known in the range proper, but its northern end is 
embayed by basaltic flows of post-Pliocene and possibly late Quater- 
nary time. The mineral deposits are found particularly at the base 
of the Middle Cambrian Ute limestone, the position of which is shown 
in the generalized section which follows. 

^ Feato, A. C, Eleventh Ann. Bept. U. S. Oeol. and Geog. Boryey Terr., for 1877, 1879, pp. 587-689. 

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Generalized uction o/rocke in Bear River Range. 


Quaternary : Alluvium, travertiBe, basalt flows ? 

Tertiary (Pliocene?): Marie, marly limestonee, and calcareous 

conglomerate ? 

Tertiary (Eocene) : Sandstones, conglomerates, and limestones — ? 

Jurassic: Twin Creek limestone (shaly limestone) 3, 500 

Jurassic or Triassic: Nugget sandstone (dark red to white sand- 
stone and quartzite) 1,900 

Triassic or Carboniferous: 

Ankareh shale (a red-bed horizon) 1, 500 

Thay nes limestone 2, 000 

Woodside shale 1, 000 


Pennsyl vanian : 

Park City formation (chert, phosphatic shales, and lime- 
stone) 600 

Weber quartzite 1, 000 

Morgan formation 500 

Mississippian li 200 

Limestone, upper Mississippian age ? 

Madison limestone ? 

T)evonian: Jefferson limestone ? 

Silurian: Limestone ? 

Ordovician: Quartzite and limestone ? 

Upper Cambrian: * St. Charles limestone (bluish-gray to gray are- 
naceous limestones, with some cherty and concretionary layers, 
passing at the base into thin-bedded gray to brown sandstones) . . 1, 197 
Middle Cambrian: 

Noiman limestone (light-gray to dark lead-colored arenaceous 

limestones) 814 

Bloomington formation (bluish-gray, more or less thin-bedded 
limestones and argillaceous shales; small roimded nodules 
of calcite are scattered irregularly through many of the 

layers of limestone) 1, 162 

Blacksmith limestone (gray arenaceous limestones in massive 

layers) 23 

Ute limestone: 

Blue to bluish-gray thin-bedded fine-grained limestones 
and shales, with some oolitic, concretionary, and inter- 

formational conglomerate layers 731 

Spence shale member (argillaceous shales) 30 

Langston limestone (massive-bedded bluish-gray limestone, 

with many round concretions) 30 

Brigham quartzite (massive quartzitic sandstones) 1, 000 


The principal mineral deposits visited are described in geographic 
order from south to north. 

1 The details regarding the Cambrian formation are taken from Waloott, C. D., Nomenclature of aom6 
Cambrian Cordllleran formations: Smithsonian Inst. Miso. Coll., vol. £8, 1006, pp. 1-12; Cambrian sec- 
tion of the Cordllleran areas: Idem, pp. 167-280. 

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The prospect on Swan Creek^ described as the 'Victoria No. 1^ is a 
short distance south of the Utah-Idaho hne. It is said to be the 
center of a group of eight claims. The wall rock is massive lime- 
stone. The ore consists of malachite; azurite, accompanying barite, 
and calcite in a much brecciated zone approximately parallel to the 
stratification of the beds. RecrystaJlization or marbleizing of the 
limestone is shown at the same horizon 100 yards or more to the 

The amount of ore at this place has not yet been proved to be 
sufficient to make a commercially valuable property. It is reported 
that prospecting has been carried on for some 16 or 17 years in the 
vicinity,and it can not 
be said that any de- 
posits yet shown are 
promising. The lo- 
cality is of interest, 
however, as showing 
the continuation of 
the mineralized zone 
in association with 
these sedimentary 



mine is located on St. 
Charles Creek, some- 
times called Big 
Creek, about 3^ miles 

west of the town of Fioube so.— Topographic map of vicinity of Blackstone mine, west of 
oi J. /-I t 1 J St. Charles, Idaho, showing rock outcrops. 

ot. Cnarles, and 

nearly on the eastern boundary of the Cache National Forest. (See 
fig. 30.) It is owned by the Blackstone Mining & Power Co. (Ltd.), 
a corporation controlled by Edgar B. Cloud, of Twin Falls, Idaho. 
When it was visited by the writer in October, 1910, preparations 
were being made for undertaking further work on the several claims. 
The discovery of the deposits in this vicinity is attributed to R. S. 
Spence, of Evanston, Wyo. The only shipments from the property 
are reported by W. H. Cloud to have been made in 1896 and to have 
consisted of 3 carloads of hand-picked or ''slab" galena runnii«g 80 

I Notes of Hoyt S. Gale, 1900. 

Contour interval 50 feet 

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per cent of lead and of 16 carloads of concentrates averaging 78 per 
cent of lead. The property at that time was controlled by W. M. 
Dodge and operated by W. M. Raht under lease. The concentrating 
mill erected by Mr. Raht burned and no shipments have been made 
since that time. 

The ore as seen at the Blackstone mine consists of crystalline 
aggregates of galena, much broken and surrounded by a thin altera- 
tion zone of dark-colored cerusite, the whole held in a gangue com- 
posed of iron-stained limestone with a small amount of siderite. The 
galena after exposure has a bluish tinge on cleavage surfaces, which 
is due to the presence of an extremely thin film of lead carbonate. 
The only other minerals from the mine seen were a few flecks of 
pyrite in a matrix of gray crystalline dolomite and a dark substance 
which on examination seems to represent renmants of the dolomite 
prior to its recrystalhzation. In some of the openings on the north 
side of the creek the ore is of similar character, except that galena 
does not appear to be so abundant and its alteration to the dark 
structureless cerusite is more complete and the carbonate of iron is 
present more prominently in the matrix. In one of the prospects 
wax-yellow tabular crystals of wulfenite, lead molybdite, are asso- 
ciated with the galena. Sphalerite in rich brown rounded crystals 
was also noted, but only in small quantities. The ore of the Black- 
stone mine is said by the present owners to be nonargentiferous and 
zinc-free; the prospects to the north carrying traces of zinc are 
reported to contain gold and silver values which tend to offset the 
lower percentage of lead. However, R. N. Bell,* State inspector of 
mines, states that the ore runs about 27 per cent of lead and 50 
cents in gold and 4 oimces in silver to the ton. He also notes that the 
shipment of 3 carloads mentioned above was probably the highest 
grade of lead ore ever shipped from the State. 

Little opportunity was found to study the nature of the ore bodies 
in this region except in the Blackstone mine, and the examination 
made here was by no means as thorough as could be desired. The 
rocks in the mineralized area strike N. 20^ W. and are cut by a set 
of nearly vertical fissures which strike N. 60° W. and appear to dip 
northeastward — that is, the fissures dip into and strike about midway 
between the strike and the dip of the beddiog of the hmestone. In 
a portion of the mine a fissure with a trend slightly east of north 
limits the ore body on the west. The mineralized area appears to be 
tabular, and its longest dimension is parallel to the strike of the sedi- 
ments. The top of the ore body is determined by a limestone 
apparently less soluble than that replaced by the ore and slightly 
dolomitic. The ore is richest toward the top. The maximum thick- 
ness of one of the richer miaeralized portions, as estimated in the 

l^tfaaimiial reported the mlniDglzidastiy of Idtbo, p. 10^ • 

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stopeB, is 8 feet measured at right angles to the roof. The mineralized 
portions decrease in richness downward and sidewise toward the 
fissures and are in these directions inclosed in iron-stained dolomite 
and limestone having a banded structure that is probably due to 

VfBUBX 31.~plaa of Blackitane mine. After aaryey by W. H. Ckmd. Shading shows ana of sfcoplng. 
Heavy broken lines show fissure systems. 

reciystallization. The bands appear to be in general parallel to the 
bedding of the limestones and are from half an inch to an inch thick. 
The ground composed of this material is said to be tight and veiy 
hard to break. The heading of the main tunnel is at present in this 
banded groimd, but it is expected to encounter, about 50 feet farther 

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in, an ore body which makes an exceQent showing of ore on ihe 
surface of the hill above. 

The developments of the Blackstone mine comprise some 800 feet 
of tunnels and drifts. The area of the stopes was not calculated, 
and no attempt was made to estimate the quantity of ore in sight. 
The general character of the development is indicated in figure 31. 


On the north side of St. Charles Creek, a few hundred yards west 
of the Blackstone mine, a tunnel has been driven in a northerly 
direction for about 200 feet, and at 75 feet from the entry a 125-foot 
drift branches off in a westerly direction but gradually swings to the 
north. The ground opened by these workings is apparently barren. 
Nearly north of the main tunnel of the Blackstone there are a num- 
ber of shallow inclines in which recent assessment work has been 
done and from one of which the wulfenite specimens mentioned 
elsewhere were obtained. 


The group of claims clustered about the Idaho Gem, on the side of 
Dry Canyon (fig. 30), were idle at the time of the writer's visit, but 
evidence of recent work was abundant. A shaft equipped with a 
horsepower hoist had recently been opened and an attempt made 
to cut some leads of ore that are disclosed in pits and are thought to 
pitch toward the shaft. Little evidence of values was found on the 


In sees. 18 and 19, T. 14 S., R. 43 E., on the divide between Bloom- 
ington Canyon and Paris Canyon, a number of pits, some of which 
are 30 or 40 feet deep, show thin, nearly vertical mineralized zones 
or bodies 3 inches to a foot in thickness, with an east-west trend. 
The nature of the values was not evident on inspection and no report 
on them was obtained. Limonite and quartz appear to be the only 
minerals present in visible amounts, suggesting that the openings 
are on gossan rather than ore. 



The Humming Bird mine, in Paris Canyon, is the center of a group 
of claims situated near the northeast comer of T. 13 S., R. 42 E., 
Boise meridian. Several hundred feet of tunnels, inclines, and shafts 
have been driven on this property, and a considerable amount of ore- 
bearing rock has been thrown out on the dump. Ore has been 

I Notee of Q. R. Mamflrtd, I9ia > Notcii of Hoyt 8. Gal^ 1608ti 

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shipped from several properties in the vicinity, but none of these 
properties have been r^ularly worked on a commercial basis. 

Tlie ores occur in association with the sedimentary series, chiefly 
Cambrian limestone and thin-bedded shales. Prospecting has traced 
similar mineralization for many miles along the north-south outcrop 
of these formations as exposed on the east side of the Bear River 

There appear to be at least two zones of mineralization in upper 
Paris Canyon, an eastern lead-bearing "belt" and the western copper 
veins, to which the Hummingbird belongs. The developments on 
the Hummingbird afford some evidence as to the character of these 
ore bodies. The vein trends N. 60° W. and dips 40° W., as developed 
in the lower entry. It lies approximately paraDel to the bedding in 
an area of intense compression folds and overthrust faults. The ore 
body is presumed to occupy a bedding thrust, and it is not known 
whether the section is there in normal or in overturned position. 
The vein is continuous throughout the extent of the present workings 
and is several feet thick. 

The ore consists of brecciated quartz and jasper vein material, in 
which are secondary quartz and malachite deposited contemporane- 
ously. It contains tetrahedrite-tennantite (gray copper ore) reacting 
in the close-tube test for both antimony and arsenic. There are also 
secondary veins of azurite and some patches of radially fibrous 

The possibility of the use of this ore as gem or ornamental stone 
has been suggested.^ Some of this material was cut and polished, and 
a thin section was examined by Sterrett, who gives the following 

The consdtuent mineoals are quartz, with a very fine red dust pigment and nutla- 
chite. Under the microscope the quartz is seen to be granular, with close-fitting 
grains, and is dusted full with minute red specks, probably hematite. The malachite 
is in bright-green grains and masses with a radial fibrous and occasional spherulitlc 
crystallization. The quartz incloses numerous small grains of buhrs of malachite 
bristling with needles. In the hand specimen the nx;k is bright jaspery red, with 
dark-green splotches thrcmghout. The quartz is close grained and tough and takes a 
good polish. The malachite is softer, though sufficiently hard to be polished along 
with the quartz. The contrast between the two colors is pleasing and for use in small 
ornaments, as inkstands, paper weights, etc., the rock would serve well. It is also 
probable that it would be accepted as a gem for scarfpins, brooches, etc. 

A prospect pit southeast of the Hummingbird mine showed a con- 
siderable amount of very pure galena. This occurred in rounded 
masses, many of them several pounds in weight, embedded in the 
residual soil adjacent to one of the limestone outcrops. The lime- 
stone itself contains large masses of pure-white calcite. This deposit 
has been but recently discovered and little work has been done upon it. 

I StOTratI, n. B., Qcmauid pnoloQi ttoncf: Mlnecal BenmoeB U. 8. for UOO, pt. 2, 1911, pp. 78M0S. 

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Several prospects were visited in the Boulder-Bonanza group, 
which is situated a mile or more north and east of the Hummingbird 
mine. One of these prospects showed lead ore, not, however, in 
place, the prospect shaft showing a mixture of soil and loose bowlders 
to a depth of 15 feet or more. This vein is said to lie in a ''belt" 
east of the Hummingbird or copper-bearing *'belt." Some of the 
ore taken from the Boulder-Bonanza claim shows vein material com- 
posed of breccia ted white quartz and j asper, somewhat iron stained, con- 
taining galena in disseminated grains. It was reported that previous 
to 1909 a total of 13 tons of ore had been shipped from this claim and 
that this had yielded a good percentage of lead. There was little 
evidence to be seen in the existing prospect from which to judge as to 
the size and continuity of the ore deposits. 


A group of prospects situated 3} miles west of Liberty, Idaho, was 
only partly examined. These prospects possess the same general 
character as the groups already described, which are localized in 
limestones. The banded recrystallized structure similar to that in 
the Blackstone mine is prevalent. The stratigraphic position of this 
particular group of prospects is definitely located at the base of the 
Ute limestone of Walcott's ^ Liberty section, which was measured at 
this place. 


Northwest of Bern, in sec. 26, T. 12 S., R. 43 E., E. A. Jonely has 
a prospect from which he reports values in gold, silver, and lead rang- 
ing from 70 cents to $20 a ton. This prospect is located near the 
margin of the thrust block and west of the axis of a small anticline in 
dense bluish-black limestone. The prospect, well named the Tiptop, 
is situated on the highest point in sec. 26. It consists of a 125-foot 
shaft, a 60-foot drift or crosscut to the west at the 100-foot level, and 
at the 125-foot level a 110-foot crosscut to the northeast, which was 
only started at the time the prospect was visited. The shaft is in 
bluish-gray limestone, except for a few feet near the top, where it 
passes through a clayey wash. The western 20 feet of the crosscut 
on the 100-foot level is in a red and blue clay or talcose selvage 
which is reported to contain values. The crosscut on the 125-foot 
level is said to have cut several mineralized fissures, and at its head- 
ing, nearly under the crest of the fold, iron oxide containing free 
gold was found. The prospect is equipped with a horse-power hoist 
and shaft house. 

I Waloott, c. D., loo. dt 

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Openings in the Tertiary lake beds, probably Pliocene^ were seen in 
the NW. i NE. \ sec. 35, consisting of a now partly filled tunnel, a 
shaft, and several shallow holes. No evidence of mineralization 
could be observed and no reports were heard concerning the nature of 
the values. A considerable expenditure had, however, evidently been 
made within the last 5 or 10 years. 

In the SE. i NW. J sec. 26 a tunnel extended for about 80 feet into 
a white marly limestone which was somewhat sheared and slickensided 
in some places. The only mineralization evident consisted of a thin 
bluish dendritic deposit, probably pyrolusite (manganese oxide). 
The tunnel gained only a few feet of cover and the roof at the face had 
caved, making a natural upraise to the surface. Mr. E. A. Jonely, of 
Montpelier, reported that assays showing gold values had been 
obtained from samples at this place. The greater number of assays 
indicated about 75 cents in gold to the ton. 

Similar prospects were seen in the eastern part of sec. 22. The only 
difference noted is that the country rock consisted of a calcareous 
conglomerate. No values were evident at this place. 


A group of copper prospects about half a mile southwest of Nounan 
post office show copper carbonates, malachite and azurite, and the 
silicate, chrysocoUa. The country rock is a gray dolomite which 
weathers brown and the soil derived from it has an iron-red color. 
The bedding of the rock is indistinct, but the strike seems to be about 
15^ east of north and the dip about 65^ E. The ore appears to be in 
fissures filled with quartz; some of these strike N. 65° W. and have 
an easterly dip of about 55°, but the attitude of others is indetermi- 
nate. The principal opening consists of a shaft, the depth of which is 
estimated at 100 feet. This was inaccessible when visited. The 
dump shows a small amount of commercial ore. 

Somewhat more extensive prospecting of similar deposits is reported 
on Coon Creek about 1^ miles southwest of the Nounan prospects, but 
these were not visited. 

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By Rowland Bancroft. 



The Metaline mining district has the following boundary, as 
recorded in the office of the county clerk of Stevens County: 

Beginning at the northeast comer of township 40 and the southeast comer of rangr 
45; thence south along the east line of range 45 to the south line of township 38 ; thence 
west along the south line of township 38 to the west line of range 42; thence north 

along the west line of 
range 42 to the south line 
of township 40; thence 
east along the south line 
of range 40 to the east 
line of range 42; thence 
north on the east line 
of range 42 to the inter- 
national boundary line; 
thence east on the inteD> 
national boundary line 
to place of beginning. 

The district, 
which covers about 
400 square noiles of 
unsurveyed land, 
occupies a comer in 
the extreme north- 
eastern part of the 
State of Washing- 
ton, the State of 
Idaho lying to the east and British Columbia to the north. (See fig. 32.) 
The western part of the district is cut by the valley of Clark Fork' 
of Columbia River and the most accessible and probably the best- 
developed properties lie within a mile or two of this stream. The 
elevations in the district range from about 2,000 feet at the river to 
6,000 feet or more on top of the highest peaks. 

I This |>aper Is a preliminary report on the writer's investigation in this field and is subject to revision. 
•This stream is known looally as Fend Ovellle BlTor. 


FiQiTBB 32.— Index map of a part of Washington, showing the location of 
the Metaline mining district. 

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The town of Metaline is on the west bank of Clark Fork, some 2 
miles south and 4 miles west of the center of the district, and is 79 
miles in an air line due north of Spokane. Just across the river, 
on the east bank, the new town of Metaline Falls has recently been 
built near a partly completed cement plant. In each place accom- 
modations can be obtained and general-merchandise stores are numer- 
ous. The population of both towns in July, 1910, probably did not 
exceed 500. 


Until 1910 the Metaline mining district was one of the most isolated 
in northeastern Washington, being more remote from railroad trans- 
portation than any other part of Stevens County. Previous to 1910 
craft on Clark Fork were used for transporting materials and supplies 
between Newport, which is 9 miles north of the southeast comer of 
Stevens County, and the Metaline district. Stages, laimches, and 
tugboats were necessary features of the last 7 nules of the journey 
northward from lone to Metaline as late as October, 1910, the total 
distance between Newport and Metaline being about 60 miles by 
the route traveled. A stage road from Colville was also used to 
reach the district, but this route involved about 50 miles of travel 
over rather poor roads. 

With the completion of the Idaho & Washington Northern Rail- 
road to Metaline Falls in October, 1910, a much cheaper and more 
eflScient means of transportation was afforded throughout the dis- 
trict, the properties located on the east side of the river being espe- 
cially benefited. The railroad has not yet published freight rates 
on ore to be shipped from the district. 


Lack of transportation and low-grade base ores have no doubt 
had much to do with the small progress made in developing the 
several properties in the Metaline district. Although there are many 
prospects in the area only a few have 300 feet or more of underground 
development, and no one of these is reported to have shipped over 
a few tons of ore. In general the district has been explored by means 
of surface cuts and trenches. If these have imcovered ore bodies 
persistent enough to warrant deeper exploration it has in places been 
attempted. The results thus far have not been gratifying, but the 
developments are still too meager to warrant final -conclusions con- 
cerning the extent of the ore bodies. 

Wagon roads are scarce in the district, practically all of the claims 
being reached by trails, and at the time of the writer's visit to the 
camp it was almost impossible to obtain saddle horses or any other 
means of conveyance. TVith the completion of the cement plant and 

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the extension of the railroad many improvements may be expected 
in the district. At the time of the investigation this was the least- 
developed camp in Stevens County. One small concentrating Tnill 
had been erected to work the ores of the Spokane Lead Co., and this 
mill is reported to have been a failure. 


The most prominent topographic feature in the Metaline district 
is the valley of Clark Fork. This stream, which flows northward 
in a course that lies 6 miles west of the center of the district, is far- 
famed for its waterfalls, swift eddies, and box canyons, all of which 
preclude extensive water transportation on the river north of Metaline 
Falls. The cliffs along the river become prominent near the southern 
boundary of the Metaline district and grow more conspicuous through- 
out the northward course of the stream, which, though a mile wide 
in part of its course farther south, is in this r^on confined in one 
place between walls reported to be only 18 feet apart. The rocks 
that form the banks of the river rise rather abruptly to benches 
ranging in height from 150 to 350 feet, and above these benches rise 
steep timber-covered mountains, the highest of which attain alti- 
tudes of 6,000 to 7,000 feet above sea level, or 4,000 to 5,000 feet 
above the river. Tlie mountains on the west side of the river form 
a continuation of the Calispell Range; the mountains on the east 
side are not known by any generally accepted name. 

Smaller mountain streams, tributary to Clark Fork, are numerous 
in this district, the more prominent being Sullivan and Slate creeks 
on the east side, flowing approximately west; and Flume, Evarts, 
and Perry creeks on the west side, flowing east or southeast. These 
streams are exceedingly valuable for generating power and for many 
other purposes, their valleys having in places high gradients. 


The geologic section exposed by the erosion of Clark Fork and its 
affluents, so far as it was seen in a visit to the prospects from Metaline 
some 8 or 10 miles northward, consists of a thick series of more or 
less dynamometamorphosed sedimentary rocks composed essentially 
of shale and dolomite. The rocks are beUeved to be of Paleozoic age, 
although no fossils were found to substantiate this conclusion. 
Igneous rocks were not observed in the localities visited. The beds 
throughout a lai^e part of the section examined have a more or less 
general north-south strike and a fairly constant westward dip at a 
steep angle. Li many places the strike is several degrees east of north 
and the dip is to the northwest or southeast. Local changes in the 
direction of strike and dip were observed and there is some intricate 
folding on a small scale. 

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Observations of the rock formations in the district were practically 
confined to a narrow strip of country near Clark Fork, but investi- 
gations in the contiguous Northport district and elsewhere in north* 
eastern Washington indicate that these metamorphosed sedimen- 
taiy rocks are simply a continuation of the series so universally 
present in the eastern part of Stevens County. Accurate measure- 
ments of these sedimentary beds were not made, but it is certain 
that they are several thousand feet thick. The rocks observed are 
mainly lime shales or slaty argillites, with intercalated dolomite 
which is in places completely silicified. These rocks occur in alter- 
nating beds of shale and dolomite, which appear to be conformably 
interbedded, the thickness of the intercalated shale or dolomite strata 
varying from a few inches up to several hundred feet. In general 
thin beds of dolomite occur between beds of shale, though the reverse 
arrangement is seen in some places, and the shale probably occupies 
the greater part of the MetaUne district. On the west side of the 
river dolomite is prominent, and in several places it extends across 
the valley and forms high cliffs and mountains on the east side. 
Much of the dolomite resembles limestone and some of it was regarded 
as limestone in the field. However, analyses of three specimens col- 
lected from widely separated localities showed the presence of 17 
per cent or more of MgO, and therefore all these rocks are termed 
dolomites, although there are probably in the area pure limestone 
strata which the writer did not recognize as such. Some cliffs in 
the vicinity of the Clark property are composed of nearly pure cal- 
cium carbonate. Here huge blue and white calcite crystals, some 
of them 3 inched long, form strata several feet in width and over 100 
feet in height. The calcite is crystallized in perfect form and shows 
no notable change due to subsequent movement. The formation 
appears to be the result of a complete recrystallization of limestone 
under rather exceptional conditions. 

As the rocks strike generally north and south the river has in 
many places cut its channel nearly parallel to the direction of the 
strike, and the steep cliffs and box canyons suggest faulting or slip, 
ping along the cleavage planes of the shales. Faulting and breccia-^ 
tion of the country rock are common and are important factors to 
be considered in connection with the ore deposits, having controlled 
to a large degree the extent and location of the mineralized areas. 

The dolomite is in general of fine, even texture and varies in color 
from the predominating bluish-gray tone to white and in places to 
a dense black. 

The dark variety contains 21.6 per cent of MgO and 27.9 per cent 
of CaO, as shown by the analysis of a sample taken from the vicinity 
of the Lead King prospect. The lighter-colored dolomites contain 
approximately 1 7 per cent of MgO and 30 per cent of CaO. The shales 

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are in general dark blue or black in color and are finely cleavable, the 
planes of lamination being distinct and close together. In places 
greenish shales were noted, which may be chloritic. The Inland 
Portland Cement Co., of Allentown, Pa., has kindly furnished the 
following analyses made by it of the shales in the vicinity of Metaline 

Analyses of^itdesfrom Sullivan Creek, Metaline Falls, 












2a 82 


A|iiiTnini( aod iron oxide 


Lixn^ ciurho'iatP ,..,,,.,-,,, . . ^ - ^ 



IgnTtion loes , , -,....-.-,-, ^ ,.,. ^ ., , , . . , 


Analyses of shales from Sand Creek, 5 miles soxUh of Metaline Falls, 














Alumina and Iron oxid* ... - - 


Lime carbonate ,..,..,,,-- , 


Macn^^ia carbonate ,..,.,...-,-,---,,,,, . , , 






Because of the small amount of development work done on pros- 
pects in the Metaline district and the general unsettled conditions 
which exist there, the character and distribution of the ore deposits 
are rather difficult to ascertain. Examinations were made of the 
Schellenburg, Riverside, and Meade properties, on the east side of 
Qark Fork, and of the Cliflf, Lead King, Clark, and Oriole prospects, 
on the west side. The deposits on these properties are reported to be 
typical of the lead and zinc deposits in the Metaline district. They 
are all within a short distance of Clark Fork, extending from Metaline 
10 miles northward. 

In general the deposits are irregular, disseminated replacements of 
lead and zinc ores in dolomite. Scattered bimches and pockets of 
galena also occur. One large fissure vein was seen. There is no visi- 
ble connection between the pockets of galena and any mineralizing 
agent, but the zinc ores in this district almost invariably accompany 
a rock that is either silicified dolomite or limestone, it being impossible 
to determine its original character. Especially worthy of note is the 
relation of the mineralized areas to the brecciated and faulted zones, 
marked disturbances in the sedimentary rocks having been noted in 
all the deposits examined. Where brecciation was the most severe 

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mineralization appears to be correspondingly high. That these zones 
of moyement indicate the former existence of channels in irregular 
fractures through which mineralizing solutions have passed is clearly 
shown by the intimate association of the ores of the district with such 
fracture zones and cemented breccias. 

The principal minerals occurring in these disseminated deposits 
are cube galena and light-colored sphalerite, the latter in places 
possibly containiag some cadmiiun. The resemblance of much of 
the sphalerite to that of the Joplin district, Missouri, is noteworthy. 
"Steel" galena and the ordinary dark-colored sphalerite, ''black- 
jack,'^ are also present in some of the ores. Pyrite and marcasite are 
found in many of the deposits, the quantity present varying greatly 
from place to place. As a rule the pyrite appears to occupy fissures 
rather than to be generally disseminated through the sedimentary 
rocks. Some chalcopyrite occurs in a few of the deposits. The 
oxidation products of the sulphides above mentioned are common, 
smithsonite and anglesite having been seen in the ores from many of 
the workings. CalamtQe was not definitely recognized, but it has 
been reported from the district and there is no reason to doubt that 
it is present. Cerusite also forms a part of the ore. Malachite, 
azurite, and limonite are less conspicuous minerals in the dissemi- 
nated deposits. 

In the property whose vein occupies a large fissure the mineraliza- 
tion by pyrite is much more profuse, and the iron sulphides, which 
elsewhere but sparingly replace the country rock, here occur in a vein 
from 2 to 8 feet in width. The amount of galena and sphalerite is 
scanty, and secondary oxidized products fill some of the small fissures 
and fractures in the country rock adjoining the vein. 


About 7 miles west of Clark Fork, near the border between the 
Metaline and Northport mining districts, a great area of granite was 
seen, similar in many respects to that in the Old Dominion mine, 
7 miles east of Colville, and in fact resembling the granite found in 
places throughout northeastern Washington. Specimens of molyb- 
denite which have been sent to the United States Geological Survey 
from a prospect located 4 miles east of Clark Fork, in sec. 18, T. 
37 N., R. 43 E., show every indication of a pegmatitic origm, which 
also implies the presence of a granitic magma in this part of the area. 
The silicified zones of dolomite or limestone are evidently the results 
of siliceous solutions. These solutions may have accompanied the 
granitic intrusions seen throughout a large part of northeastern 
Washington, tongues of which probably extend into the Metaline 

94174**— Bull. 470—11 13 

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The light-colored sphalerite is almost invariably found in silicified 
zones in this district. As the lead and zinc ores are commonly 
associated in this locality, it seems only reasonable to suppose that 
the sDiceous solutions brought also the lead ores. The apparent 
uniformity of the deposits and the geologic section throughout the 
portion of the area examined and the probability that a similar 
geologic series extends over a greater part of the district seem to 
justify the conclusion that deposits elsewhere in the Metaline region 
are of the same general nature as those examined. 


At the time of the investigation (August, 1910) the Metaline 
district was more sparsely settled than any other locaUty investigated 
in northeastern Washington. In December, 1910, direct railroad 
transportation was available for some of the properties on the east 
side of Clark Fork. There are no wagon roads in practically the whole 
of the district, and the traDs to the several properties do not aflFord 
an economical means for shipping out the ore. 

All the deposits examined were of extremely low grade, none of 
them showing over a small percentage of lead or zinc, so that shipping 
without concentration would probably be improfitable even with 
railroad transportation at the properties. One mill has been built, 
which proved a failure. Whether others can be constructed so that 
the ore minerals can be economically saved is an open question. 
Many tons of ore would have to be mined to produce 1 ton of concen- 
trates containing roughly, say, 50 per cent of lead and zinc. It is 
the writer's impression that in most of the prospects examined the 
ratio of crude ore to such a concentrate would be about 30 or 40 to 1, 
which means a high initial expense of installation and much wear 
and tear on the milling machinery. The mineralization is scattered 
and irregular, and at present the boundaries of the mineralized areas 
are unknown. 

In prospecting other areas in the Metaline district it would be well 
to look for zones of intense brecciation and faulting in the coimtry 
rock, accompanied by local silicification. The lead and zinc ores 
seem to have been introduced by solutions accompanying the intru- 
sion of the granite bathohth, and it is highly probable that mineralizar 
tion has taken place along fissinres and fracture zones that have been 
more or less closely followed by the solutions accompanying the 
acidic magma. Some operators in the district beheve that contacts 
between light and dark dolomite, or between dolomite and shale, are 
favorable places to look for ore bodies. This may be true of contacts 
contiguous to zones of intense movement, but elsewhere such con- 
tacts are likely to be barren. 

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Comprehensive smelter and mill tests have not, to the writer's 
knowledge, been made on ores from this district, and it is essential, 
before erecting plants to treat the ores, to make a thorough investiga- 
tion of the chemical and physical properties of the constituent 
minerals of the ore bodies. Until recently it was not generally known 
that zinc minerals occurred in this district. From observation the 
zinc minerals seem to be as widely disseminated in the ore deposits 
as the lead ores, although heretofore the district has been considered 
as principally a lead camp. It is possible that as greater depth is 
reached in future developments a complete change in the mineral 
character of the ores may be revealed, so that mills erected with 
the present meager knowledge of the ore occiurences throughout the 
district would prove unsuitable. 




The Oriole property is located about 1 mile due west of Metaline 
and some 700 feet above it, the camp being at an elevation of 2,750 
feet. The workings start near the base of steep dolomite cliflFs which 
iBank mountains that attain altitudes of several thousand feet, form- 
ing some of the highest peaks in the vicinity. These mountains are 
about a mile back from the river and form the eastern front of the 
Calispell Range. The camp is located on a small flat near the head 
of a minor gulch. The equipment consists essentially of a small com- 
pressor plant and a boiler. 

The rocks encountered in the workings are fine to medium grained 
grayish-blue dolomites, which are locally more or less silicified. 
They strike approximately north and south and dip about 45° W. 
or NW. The main level has been started at a point several hundred 
feet south of the camp and approximately 100 feet higher. It con- 
sists of an adit tunnel some 250 feet long, driven in a westerly direc- 
tion in the east slope of the ridge above referred to. A sUp or fault 
in the country rock was encountered at this distance from the portal 
and a drift reported to be 250 feet long has been driven on this slip, 
which trends N. 70° W. and dips 70° NE. 

The minerahzation in the prospect has been confined to the fault 
plane, the width of which varies from practically nothing up to 12 
inches, or in places perhaps a little more. The gangue is principally 
gouge, with here and there some irregular stringers of quartz, which 
in places nearly fill the space between the waUs. Some calcite was 
noted in parts of the vein. The ore minerals appear to be chiefly 
sphalerite and galena, but some pyiite is scattered in a very irregular 

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pockety manner throughout the quartz, the vein as a whole being 
exceptionally lean. A few fairly massive pockets of ore were seen, 
one of which measured as much as 12 inches across. A little ' 'steel '^ 
galena was seen in a few of the ore specimens. A winze, said to be 
65 feet deep, is located near the center of the drift. This winze is 
now nearly filled with waste rock. Near the top of it are two small 
quartz veins, separated from each other by 12 inches of country 
rock, the total width of the veins, including the horse, being about 
30 inches at this place. This lens of ore exposed in the top of the 
winze is of uncertain relation to the main fault seen in the drift 
above referred to. The country rock contains many small fractures 
that traverse it in all directions. 

The upper workings, located at an elevation of 2,950 feet, a little 
north of the lower level, consist of a 30-foot adit tunnel and a 20-foot 
drift on a slip in the country rock which strikes N. 70° E. and dips 
45® NW. Here a vein having an average width of 6 inches but 
attaining a maximum of 24 inches in the bottom of an 8-foot winze 
shows some mineralization by galena, sphalerite, chalcopyrite, pyrite, 
and the oxidation products limonite, azurite, and malachite in a 
gangue of quartz and gouge. 

The ore is reported to carry appreciable values in sjlver and a little 
gold, in addition to the lead and zinc. 

In general the ore body is lenticular and not at all persistent. 
This property has more underground development than any of the 
others visited in the Metaline district by the writer. 


About 2i miles north of Metaline, on Flume Creek near its con- 
fluence with Clark Fork, is a group of claims known locally as the 
Clark property, controlled by the Metaline Lead Co. A wagon road 
extends northward from Metaline to Flume Creek half a mile west of 
the prospects, and good trails have been built from tliis place to the 
workings along the north side of the creek. Exploration, principally 
by means of stripping, trenching, and open cuts, is being carried on 
along the cliffs which lie directly northwest of the junction of Flume 
Creek and Clark Fork. These cliffs rise rather steeply from an 
elevation of 1,970 feet at the river channel to 2,800 feet or more on 
top of the first prominent bench or ridge and are cut by gorges from 
100 to 600 feet deep, through the most precipitous of which courses 
Flume Creek. Because of its relatively steep fall in the distance 
traversed, Flume Creek affords an excellent opportunity for generating 

The claims constituting the Clark property number about 20. 
The principal surface development is on the Josephine claim, which 
includes within its boundaries part of one of the high cliffs above 

Digitized by 


WASH. 197 

referred to. On this claim there are 18 or more surface cuts, a 
short tumiel, and a shallow shaft. About 400 feet lower, just above 
the stream bed of Flume Creek on the Hidden Falls claim, are two 
adit tunnels, one on each side of the creek, driven in opposite direc- 
tions some 270 and 340 feet. These have been started with a view 
to prospecting the cMs and possible ore bodies at this depth. So far, 
however, mineralized rock is not reported to have been encoimtered. 
Still farther down, near the level of Clark Fork, are an open cut 
and an adit tunnel some 300 feet long on the Chickahominy claim. 
This tunnel has been driven on a fault plane in the dolomite series 
near which occur scattered pockets of the ordinary lead and zinc ores 
found in the district. On each of the other claims in the group a 
small amount of work has been done, consisting mainly in sinking the 
discovery shafts, the title of the whole group being held by work 
concentrated on one or two claims. 

The rocks exposed by the workings are the light-colored dolomites, 
dark shales, and calcite ( ?) strata referred to in the general description 
of the geology of the district. The strike and dip of these strata are 
difficult to ascertain. The general direction of the strike is northeast 
and that of the dip northwest. 

The ore minerals are chiefly sphalerite and galena; the oxidation 
products smithsonite, cerusite, and anglesite are prominent in certain 
parts of the outcropping strata. No regular veins of ore-bearing 
material were found and the extent of replacement in the country 
rock is undetermined. The ores occur as pockets in dolomite and 
disseminated through brecciated and silicified country rock, and it 
is impossible to give authentic data on their probable extent. In 
places the mineralized zone appears to be at least 10 to 20 feet wide 
and to extend 50 to 100 feet along the strike of the strata. 

The mineral-bearing rock contains little silver and is of low grade, 
so that concentration would be necessary; during this operation a 
partial separation of the lead and zinc minerals would be effected. 
It is an expensive ore to handle and for profitable mining considerable 
machinery would have to be installed ; this means a large initial outlay 
of money. 


The Lead King property, also controlled by the Metaline Lead Co., 
is located on the west side of Clark Fork some 6 miles north of 
Metaline, at an elevation of approximately 2,600 feet. The wagon 
road built by the company has been partly completed for a distance 
of about 4 miles and is connected by trail with the prospect. A small 
bunk house is located near the south end of the claim. 

The country in the immediate vicinity of this property, unlike that 
near most of the other prospects of the district, is rather flat, the main 

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workings being located on top of a small ridge which rises a few feet 
above the first high bench west of Clark Fork. 

The principal developments consist of shallow shafts, surface cuts 
and trenches, and two short tunnels, the longer one having been driven 
about 200 feet. The rocks in the vicinity are dolomites, similar in 
many respects to those found in other parts of the MetaUne district. 
They appear to strike northeast and to dip northwest at a steep angle. 
One peculiarity of the geologic section exposed in this vicinity is the 
presence of a very fine grained black dolomite, containing 21.5 per 
cent of MgO and 27.9 per cent of CaO. This rock appears to be 
nearly barren of mineral values. The mineralization by galena and 
zinc blende seems here to be very sparse and the minerals are irregu- 
larly disseminated through the dolomite. In places calcite accom- 
panies the ores. As exposed by the surface workings in this property, 
the lead ores seem to predominate. 

All of the work done here is of so superficial a nature that few data 
were obtained as to the extent of the mineralized area. 


The Cliflf is the most northerly deposit examined by the writer in 
the Metaline district, and is located some 7 miles north of Metaline, 
on the west side of the first high bench west of dark Fork. The 
workings are situated at an elevation of 2,730 feet and are approxi- 
mately three-eighths of a mile southeast of Carmichael's ranch. 
The developments consist of a 30-foot trench in dolomitic limestone, 
this formation apparently dipping northwest at a rather steep angle. 
One shipment is reported to have been made from this property, but 
the returns were not accessible to the writer. There are no surface 
improvements, and the property is in the early prospecting stage. 

The mineralization seems to be confined to a zone of brecciated lime- 
stone, the extent of which is indeterminable. As exposed on the sur^ 
face the apparent width of this partly siUcified zone is not over 8 or 10 
feet and the mineralization is scattered and of uncertain extent. 
Galena and perhaps a little sphalerite form the ores. In general there 
seems to be less replacement of the country rock than in the Josephine 
claim of the Clark group and more segregation in vugs along the 
siliceous zone. 



The properties known as the Schellenbui^ prospects are located 
about 2i miles north of Metaline Falls, on the east side of Clark 
Fork, at an elevation of 2,550 feet. They are reached by trail or 
wagon road from Metaline Falls and up to the present time have not 

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made any shipments of note. The developments consist of surface 
trenches from 1 to 5 feet deep and from 6 to 100 feet long. From 
their proximity to the new raihx)ad which is built to Metaline Fallsi 
these properties are perhaps more accessible tihan any others described 
in this paper. 

The rocks in which the mineralization occurs are dolomitic lime- 
stones, which strike northeast and dip 70° to 80° NW. They are 
typical of the series found in this district and show in the most highly 
mineralized belt considerable brecciation. 

The workings on this group expose a number of fault jUanes which 
have general northeast-southwest and northwest-southeast directions. 
Much of the mineralization throughout the area is found along the 
fault planes and appears to have accompanied or followed the more 
intense movements. The present developments are superficial and 
little can be said about the future of these deposits. 


The workings of the Riverside property, about 6 miles north of 
Metaline Falls, are situated on the face of a cliff which lises almost 
vertically above Clark Fork. The camp is located on top of the 
first bench, some 300 feet above the river. The developments consist 
of several short tunnels or drifts on or near the vein, which show in 
an uncertain manner the lateral extent of the replacement of the 
sedimentary series. Outside of the mineralized zone fresh medium 
to fine grained blue and gray dolomitic limestones form the country 
rock. A few hundred feet to the east blackish shales appear in the 
series and extend eastward for some distance. These rocks strike 
N. 66° E. and dip 70° to 80° NW. 

The deposit constitutes a true fissure vein in dolomitic limestone, 
the vein beiog exposed for a vertical distance of about 260 feet. The 
country rock is partly replaced on either side over a distance of 
several feet, and parallel fissures extend from the main vein for 15 to 
20 feet. These lateral stringers are much smaller than the main 
vein, which is in general from 2 to 8 feet wide. The trend of the vein 
is N. 66° E. and the dip 70° to 80° NW. 

The vein filling is principally pyrite with a little galena, the mineral 
aggregate showing concentric or kidney structure representing alter- 
nate replacement of the limestone by pyrite and galena. A radial 
structure is also developed in the pyrite. The iron minerals have 
been partly decomposed, so that a very heavy gossan caps the vein 
and extends downward for a distance of 100 feet or so. Gypsum 
crystals occur in abimdance along the small cracks and fissures and 
are no doubt derived from the alteration of the dolomitic limestone 
by the action of sulphuric acid liberated in the oxidation of pyrite. 
Some * 'steel" galena was noted in a small tunnel halfway down the 


zed by Google 


cliff, but farther down this mineral seems to be absent. Chalcopyrite 
was seen in the lower levels. Because of the highly oxidized condi- 
tion of the iron ores in this deposit, the strata on both sides of the 
fissure are very much stained and form a noticeable red and yellow 
zone which can be seen for a great distance. 

Although the fissure seems to be well defined and to have a per- 
sistent bearing, the vein filling is of such a nature that the lead ores 
may not occur in sufficient quantities to warrant mining. It is 
possible, however, that developments along the vein proper may 
uncover larger quantities of the lead ores, which form only a small 
part of the vein filling so far exposed. 


The Meade prospects are situated at an elevation of 2,300 feet on a 
small hill just north of Slate Creek, some 7 or 8 miles north of Metaline 
Falls. The developments consist of two short tunnels driven on 
opposite sides of the hill, each one being approximately 110 feet long. 
The country rock is dolomite or limestone similar to that noted in the 
vicinity of other prospects in the district. The mineraUzation seems 
to consist principally in the introduction of pyrite with here and there 
a bunch of galena, the latter apparently occurring along the bedding 
planes of the dolomite. The pjrrite has a radial structure. The 
main pockets of ore have been found along a slip ia the country rock, 
which strikes N. 20^ E. and dips 50° SE. A small amount of chalco- 
pyrite is present in the ore. Calcite and quartz form the gangue, which 
is locally brecciated. 

Because of tlie slight amount of development on the slip in which 
these pockets of galena occur, it is impossible to state the extent of 
the ore body. It seems highly probable, however, that this deposit 
is small and that future developments will show only a continuation 
of the irregularly spaced aggregates of ore minerals. 

Digitized by 



The following list includes the more important publications on lead 
and zinc published by the United States Geological Survey. These 
publications, except those to which a price is affixed, can be obtained 
free by applying to the Director, United States Geological Survey, 
Washington, D. C. The priced publications may be purchased from 
the Superintendent of Documents, Government Printing Office, 
Washington, D. C. 

Adams, 6. I. Zinc and lead deposits of northern Arkansas. In Bulletin 213, 
pp. 187-196. 1903. 26c. 

Adams, G. I., and others. Zinc and lead deposits of northern Arkansas. Pro- 
fessional Paper 24. 118 pp. 1904. 

Bain, H. F. Lead and zinc deposits of Illinois. ' In Bulletin 225, pp. 202-207. 
1904. 35c. 

Lead and zinc resources of the United States. In Bulletin 260, pp. 251- 

273. 1905. 40c. 

A Nevada zinc deposit. In Bulletin 285, pp. 166-169. 1906. 60c. 

Zinc and lead deposits of northwestern Illinois. Bulletin 246. 56 pp. 


Zinc and lead deposits of the upper Mississippi Valley. Bulletin 294. 155 

pp. 1906. 

Zinc and lead ores in 1905. In Mineral Resources U. S. for 1905, pp. 379- 

392. 1906. 

Bain, H. F., Van Hise, C. R., and Adams, G. I. PreUminary report on the lead 
and zinc deposits of the Ozark region [Mo.-Ark.]. In Twenty-second Ann. Rept., 
pt. 2, pp. 23-228. 1902. $2.25. 

Bancroft, Howland. Reconnaissance of tho ore deposits in northern Yiuna 
County, Ariz. Bulletin 451. 130 pp. 1911. 

Bbckbb, G. F. Geology of the Gomstock lode and the Washoe district; with atlas. 
Monograph III. 422 pp. 1882. 111. 

BouTWBLL, J. M. Economic geology of the Bingham mining district, Utah. Pro- 
fessional Paper 38, pp. 73-385. 1905. 

BuTLBK, B. S., and Siebenthal, C. £. Silver, copper, lead, and zinc in the Central 
States in 1909 (mine production). In Mneral Resources U. S. for 1909, pt. 1, pp. 
495-531. 1911.* 

Calkins, F. C, and MacDonald, D. F. A geologic reconnaissance in northern 
Idaho and northwestern Montana. Bulletin 384. 112 pp. 1909. 

Clbrg, F. L. The mining and metallurgy of lead and zinc in the United States. 
In Mineral Resources U. S. for 1882, pp. 358-386. 1883. 50c. 

Cboss, Whitman; Howe, Ebnbst; and Ransome, F. L. Silverton folio (No.l20), 
GeoL Atlas U. S. 1905. 25c. 

1 Eailtor volumes of the Mineral Resoixroes of the United States also contain discossions relating to the 
lead and sine industries of the United States. 


Digitized by 



Cross, Whitman, Spbncbr, A. C, and Ransoms, F. L. Rico folio (No. 130), 
Geol. Atlas U. S. 1905. 25c. 

Cross, Whitman, and Hole, A. D. Engineer Mountain folio (No. 171), Geol 
Atlas U. S. 1910. 25c. 

Curtis, J. S. Silver-lead deposits of Eureka, Nev. Monograph VII. 200 pp 

1884. $1.20. 
Elus, E. E. Zinc and lead mines near Dodgeville, Wis. In Bulletin 280, pp 

311-315. 1905. 40c. 

Emmons, S. F. Geology and mining industry of Leadville, Colo., with atlas, 
Monograph XII. 870 pp. 1886. |8.40. 

Ecoifbmic geology of the Mercur mining district, Utah. In Sixteenth 

Ann. Rept., pt. 2, pp. 349-369. 1895. $1.25. 

The mines of Custer County, Colo. In Seventeenth Ann. Rept., pt. 2, 

pp. 411-472. 1896. |2.35. 

Emmons, S. P., and Irving, J. D. Downtown district of Leadville, Colo. Bulle- 
tin 320. 72 pp. 1907. 

Emmons, W. H. Some ore deposits in Maine and the Milan mine, New Hamp- 
shire. BuUetin432. 62 pp. 1910. 

Grant, U. S. Zinc and lead deposits of southwestern Wisconsin. In Bulletin 
260, pp. 304-310. 1905. 40c. 

Grant, U. S., and Burchard, E. F. Lancaster-Mineral Point folio (No. 145), 
GeoL Atlas U. S. 1907. 25c. 

Haque, Arnold. Geology of the Eureka district, Nevada. Monograph XX. 
419 pp. 1892. "^5.25. 

Hahn, O. H. The smelting of aigentiferous lead ores in the fax West. In Mineral 
Resources U. S. for 1882, pp. 324-345. 1883. 50c. 

Hoffman, H. 0. Recent improvements in desilverizing lead in the United States. 
In Mineral Resources U. S. for 188^-84, pp. 462-473. 1885. 60c. 

Iles, M. W. Lead slags. In Mineral Resources U. S. for 1883-84, pp. 440-462. 

1885. 60c. 

Irving, J. D. Ore deposits of the northern Black Hills. In Bulletin 260, pp. 50- 
77. 1905. 40c. 

Ore deposits in the vicinity of Lake City, Colo. In Bulletin 260, pp. 78- 

84. 1905. 40c. 

Irving, J. D., and Bancroft, Howland. Geology and ore deposits near Lake 
City, Colo. Bulletin 478. 128 pp. 1911. 

Irving, J. D., and Emmons, S. F. Economic resources of northern Black Hills. 
Professional Paper 26, pp. 53-212. 1904. 

Keith, Arthur. Maynardville folio (No. 75), Creol. Atlas U. S. 1901. 26c. 

Recent zinc mining in East Tennessee. In Bulletin 225, pp. 208-213. 

1904. 35c. 

Lindgren, Waldbmar. The mining districts of the Idaho Basin and the Boise 
Ridge, Idaho. In Eighteenth Ann. Rept., pt. 3, pp. 625-736. 1898. |2.15. 

The gold and silver veins of Silver City, De Lamar, and other mining 

districts in Idaho. In Twentieth Ann. Rept., pt. 3, pp. 75-256. 1900. $1.50. 

A geological reconnaissance across the Bitteiroot Range and Clearwater 

Mountains in Montana and Idaho. Professional Paper 27. 123 pp. 1904. 

The Tres Hermanas mining district. New Mexico. In Bulletin 380, pp. 

123-128. 1909. 

Resources of the TTnited States in gold, silver, copper, lead, and zinc. In 

Bulletin 394, pp. 114-156. 1909. 

Lindgren, Waldbmar, and Graton, L. C. Mineral deposits of New Mexico. In 
BuUetin 285, pp. 74r«6. 1906. 60c. 

Digitized by 



LiNDOREN, Waldbmab, Graton, L. C, and Gordon, C. H. Theore depoeita of New 
Mexico. ProfesBional Paper 68. 361 pp. 1910. 

MacDonald, D. F. Economic features of northern Idaho and northwestern 
Montana. In Bulletin 285, pp. 41-62. 1906: 60c. 

McCaskey, H. D. Gold, silver, copper, lead, and zinc in the Eastern States (mine 
production). In Mineral Resources U. S. for 1909, pt. 1, pp. 638-647. 1911. 

Peppbrberg, L. J. Notes on the mineral deposits of the Bearpaw Mountains, 
Montana. In Bulletin 430, pp. 135-146. 1910. 

Ransome, F. L. Report on the economic geology of the Silverton quadrangle, 
Colorado. Bulletin 182. 265 pp. 1901. 60c. 

The ore deposits of the Rico Mountains, Colorado. In Twenty-second 

Ann. Rept., pt. 2, pp. 229-398. 1902. 

Ransome, F. L., and Calkins, F. C. Geology and ore deposits of the Coeur d'Alene 
district, Idaho. Professional Paper 62. 203 pp. 1908. 85c. 

Schrader, F. C. Mineral deposits of the Cerbat Range, Black Mountains, and 
Grand Wash Clifis, Mohave County, Ariz. In Bulletin 340, pp. 53-84. 

The mineral deposits of the Cerbat Range, Black Mountains, and Grand 

Wash ClifEs, Mohave County, Ariz. Bulletin 397. 226 pp. 1909. 

SiEBENTHAL, C. E. Mineral resources of northeastern Oklahoma. In Bulletin 
340, pp. 187-228. 1908. 

Lead. In Mineral Resources U. S. for 1909, pt. 1, pp. 181-201. 1911. 

Zinc. In Mineral Resources U. S. for 1909, pt.l, pp. 203-220. 1911. 

Smith, G. O. Note on a mineral prospect in Maine. In Bulletin 315, pp. 118-119. 


Smith, W. S. T. Lead and zinc deposits of the Joplin district, Missouri-Kansas. 
In Bulletin 213, pp. 197-204. 1903. 25c. 

Smith, W. S. T., and Siebenthal, C. E. Joplin district folio (No. 148), Geol. 
Atlas U.S. 1907. 50c. 

Spencer, A. C. The Mine Hill and Sterling Hill zinc deposits of Sussex County, 
N. J. In Ann. Rept. Geol. Survey New Jersey for 1898, pp. 25-52. 1909. 
- Spencer, A. C, Salisbury, R. D., and KCmmel, H. B. Franklin Furnace folio 
(No. 161), GeoL Atlas U. S, 1908. 25c. 

Spurr, J. E. Geology of the Aspen mining district, Colorado, with atlas. Mono- 
graph XXXI. 260 pp. 1898. $3.60. 

The ore deposits of Monte Cristo, Wash. In Twenty-second Ann. Rept., 

pt. 2, pp. 777-866. 1902. 

Descriptive geology of Nevada south of the fortieth parallel and adjacent 

portions of California. Bulletin 208. 229 pp. 1903. 

Spurr, J. E., and Garret, G. H. Preliminary report on the ore deposits of the 
Georgetown mining district, Colorado. In Bulletin 260, pp. 9^120. 1905. 40c. 

The Idaho Springs mining district, Colorado. In Bulletin 285, pp. 35-40. 

1906. 60c. 

Economic geology of the Georgetown quadrangle, together with the Empire 

district, Colorado, with gencnral geology by S. H. Ball. Professional Paper 63. 422 pp. 

Tower, G. W., and Smith, G. 0. Geology and mining industry of the Tiatic dis- 
trict, Utah. In Nineteenth Ann. Rept., pt. 3, pp. 601-767. 1899. $2.25. 

Tower, G. W., Smith, G. O., and Emmonb, S. F. Tintic special folio (No. 65), 
Geol. Atlas U. S. 1900. 25c. 

Ulrich, E. 0., and Smith, W. S. T. Lead, zinc, and fluorspar deposits of western 
Kentucky. (In Bulletin 213, pp. 205-213. 1903. 25c.) Professional Paper 36. 
218 pp. 1905. 

Various attthors . Gold, silver, copper, lead, and zinc in the Western States in 1909 
(mine production). In Mineral Resources U. S. for 1909, pt. 1, pp. 223-494. 1911 

Digitized by 



Wbbd, W. H. Fort Benton folio (No. 55), Geol. Atlas U. S. 1899. 25c. 

Little Belt Mountains folio (No. 56), Geol. Atlas U. S. 1899. 25c. 

Geology of the Little Belt Mountains, Montana, with notes on the mineral 

deposits of the Neihart, Barker, Yogo, aUd other districts. In Twentieth Ann. Rept., 
pt. 3, pp. 271-461. 1900. $1.50. 

Weed, W. H., and Babrell, JpsBFH. Geology and ore deposits of the Elkhom 
mining district, Jefferson County, Mont. In Twenty-second Ann. Rept., pt. 2, pp. 
399-549. $2.25. 

Weed, W. H., and Pibsson, L. V. Greology of the Castle Mountaios mining district. 
BuUetinl39. 164 pp. 1896. 15c. 

WiNBLOW, A. The disseminated lead ores of southeastern Missouri. Bulletin 132. 
31 pp. 1896. 5c. 

WouT, J. £. Zinc and manganese deposits of Franklin Furnace, N. J. In Bul- 
letin 213, pp. 214-217. 1903. 25c. 

"Digitized by 


Rare Metals. 


By Fbank L. Hess. 


The Brinton arsenic mine is located on the south slope of lick 
Ridge, one of the minor elevations of the Appalachian Mountains, at 
Brinton, Floyd County, Va., about 14 miles southeast of Christians- 
burg. (See fig. 33.) So far as is known this is the only mine in the 
eastern United States which has xnined arsenic ore and produced 
white arsenic from it, although arsenopjrrite h^s been mined in at 
least two places in New York for shipment to arsenic plants located 
at other points. 

The mine is reached from Christiansburg by a very good mountain 
road, on which the only steep grades are within a mile of the mine. 
According to the Survey's topographic map of this region (the Chris- 
tiansbu]^ sheet) the mine is about 2,400 feet above sea level. Sceni- 
cally the country is beautiful, and owing to its altitude it is cooler in 
the summer than lower lying lands, and several summer resorts are 
located within a few miles of the mine. 

The country is well wooded and fields left uncultivated are soon 
overgrown with trees. Wood for fuel and mine timber is therefore 
plentiful and comparatively cheap. 

Owing to the roughness of the country the tillable fields are small 
and difficult to cultivate. The soil is poor and good crops can be 
raised only with the help of fertilizers. As a result of these handicaps 
and the comparative isolation of the country many of the people are 
poor and labor is abundant and low priced. 


The arsenic deposits were found by C. E. Brinton in 1901. Work 
on the mine and on the erection of a plant for making white arsenic 
(arsenious oxide, As,0,) was begun in March, 1902. The brick 
necessary for the building of the plant, about 1,250,000, were made 
and bmned and the liunber required was cut and sawed on the place. 
The mine is equipped with a steam hoist, steam pimip, electric lights, 
and air drills. 


Digitized by 



The making of white arsenic began in January, 1903, and was 
continued intermittently for a nimiber of years. 


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In 1910 a company was organized to manufacture Paris green and 
other insecticides for which the arsenic produced at the Brinton mine 
was to be used, and a plant was established at Norfolk, Va., but is 
not yet (March, 1911) in operation. 

Digitized by 




The country rock of the region has been called by Arthur Keith * 
the CaroUna gneiss and is of pre-Cambrian age. In places the gneiss 
is coarse, biotitic, and very quartzose. It contains both blue and 
white quartz. Intercalated with the coarser phases is a dark-gray 
mica-quartz schist having many beds of lighter color. Near the 
mine only the schist was seen. 

An altered microcline granite cuts the gneiss at numerous places 
and has generally been squeezed until it also has a coarsely gneissoid 
structure. In the hasty examination made in the field the granite 
was thought to be generally of one type, but close examination of 
the specimens collected makes it seem probable that there is consid- 
erable variation. In one variety garnet is prominent. The garnet 
is crushed and forms possibly 20 per cent of the rock. Under a hand 
lens it has a dirty brownish-green color. It carries no manganese 
and, to judge from its color, probably does not contain much iron. 
Besides garnet 'the granite carries quartz, andesine, microcline, mus- 
covite, and a httle epidote. The quartz contains innumerable mi- 
nute needles of rutile. What appeared in the field to be a closely 
related rock shows under the microscope a considerably crushed, 
finely granular mass of quartz and microperthite. The feldspar has 
an exceedingly minute perthitic structure and contains a great num- 
ber of inclusions which are so small that determination is difficult, 
but which appear to be largely apatite. The rock contains a little 
biotite which is invisible to the unaided eye. 

The gneisses are also cut by many dikes, from a few inches to 2 
feet thick, of what is supposed to have been pegmatite. These dikes 
in general follow the gneissoid structure and have been squeezed 
until they partake of the same general structural appearance but are 
more or less lenticular. Other dikes which are unmistakably peg- 
matitic cut across the strike of the gneiss. Some of these contain 
both blue and white quartz; others, such as one on GifiPeys Creek, 
1^ miles northeast of the arsenic mine, contain only blue quartz 
and buff feldspar, are uncrushed, and probably later than the crushed 
dikes. White quartz veins reaching 300 to 400 feet in length are 
interbedded with and cut across the gneiss. They contain some 
muscovite and may be, in part at least, of pegmatitic origin. As 
some of them cut across the structural lines, it does not seem prob- 
able that they are segregational masses such as are often found 
intercalated in gneiss and schist. 

In the immediate vicinity of the mine the rock is a fine-grained 
gray mica-quartz schist which consists of muscovite and quartz with 
a very little epidote. On the crest of Lick Ridge, which is here only 

1 Fenonal oommanicatlon. The Carolina gnetai ia deBcnIbed by Kalth in the Cranberry folio (No. 90) , 
Oeol. Atlas 17. S., U. S. Qeol. Survey, 1903, p. 10. 

Digitized by 



a few hundred feet across, is a vein of milky quartz several feet thick. 

The ridge follows the east-west strike of the schist, which dips 40® 

to 45® S. No gneiss was noticed within a quarter of a mile of the 



The arsenic deposits consist of gray mica-quartz schist impreg- 
nated with arsenopyrite adjacent to faults along which apUte or 
pegmatite has been intruded and later crushed to schist. At many 
places south, southwest, and east of the mine there are pieces of 
spongy float rock from which arsenopyrite has evidently been weath- 
ered. In the hasty examination made by the writer the deposits 
now being worked could not be definitely followed on the surface, 
and they are not beUeved to be continuous for a great distance, but 
it is probable that similar deposits occur at a nimiber of places in the 

The mine is entered by an adit opening on the south side of the 
ridge, perhaps 100 feet below the summit and about the same dis- 
tance above the foot of the hill. At 50 feet in the adit cuts an 
impregnation vein of arsenopyrite, 2 to 8 inches thick, which dips 
with the schist. The impregnation is most dense in the middle of 
the vein, and in some places the ore forms an almost soUd mass up 
to 4 inches thick, with leaner rock for 2 or 3 inches on each side. 

A similar vein, which is thinner but richer where cut, is crossed 
25 feet farth^ in, and on this vein a drift has been run to the west. 
Beyond the drift the adit continues into the hill for 100 feet. A dam 
4 feet high has been built across it, and this portion of the adit is 
used as a cistern from which water for the reduction plant is obtained. 

Forty feet west of the adit the vein followed by the drift is a few 
inches thicker, and some ore has been taken out. From this place 
an inclined winze has been sunk 300 feet following the schist at a dip 
of 42^ S. 

Drifts have been run both east and west on levels 100 feet apart, 
but only a small quantity of ore has been found on the west side. 

On the first or 100-foot level most of the ore taken out was from 
a stope in a lens beginning about 15 feet east of the winze. The lens 
was 30 feet long east and west, of possibly the same extent along the 
dip, and 8 or 9 feet thick at most. Beyond the stope the drift extends 
for 60 or 60 feet, following the vein of arsenopyrite, which reaches 
several inches in thickness and on either side of which there is more 
or less impregnation of the country rock. The vein follows a fault 
which is not very clearly defined. In places a quartz vein 2 or 3 
inches thick occurs with the arsenopyrite, but generally a white mica- 
quartz schist reaching 5 feet in thickness accompanies the ore. 
From its composition and varying thickness, this schist is believed 
to be a squeezed pegmatite or aplite in which the feldspars have been 

Digitized by 



lai^ely altered to muscovite. The grain is fine^ but this may be due 
to the crushing. The arsenopyrite on the adit level and on the first 
and second levels is etched and the centers of the larger aggregates 
have been removed by leaching. The mineral has largely lost its 
bright metallic appearance and is nearly black. With the arsenopy- 
rite is more or less pyrite, part of which is bronzy and evidently 
carries some copper. The mine is wet^ and in places along the first 
level where water drips a thin green scum of malachite has formed. 
At one point there appeared to be a small amount of metallic copper. 

On the second level the vein probably cuts across the schists at a 
small angle, and is under the winze, which follows the dip of the 
schist. Lenses of ore similar to that on the first level described above 
have been taken out on the east side. On the third level, also, the 
winze is above the vein, and a drift has been run to the east about 75 
feet, whence a crosscut to the north was made to cut the vein. Here 
a lens of ore, said to reach 7^ feet in thickness and between 30 and 
40 feet in length, has been stoped. The arsenopyrite is not so much 
etched as in the upper levels, and in part is fresh and bright. The 
slipping plane of a fault and the crushed pegmatite are again notice- 
able on this level. The lenses of ore do not seem to follow one plane 
and are apparently along a series of more or less parallel slipping 
planes which lie close together and which may, instead of being 
parallel, cut into each other. 

An assay of a piece of ore rich in arsenopyrite, picked from the ore 
pile, showed only traces of gold and silver.^ Mr. Brinton states that 
he has had assays of $2 and more in gold and 2 to 4 ounces of silver 
to the ton of 2,000 pounds. 


In thin section under the microscope the ore shows, in nonmetallic 
minerals, only quartz and muscovite, with minute inclusions of apa- 
tite and here and there a crystal of zircon. The arsenopyrite shows 
none of the perfect bipyramidal forms in which it generally occurs in 
igneous rocks, but has irregular outlines, though in some places there 
is a tendency toward skeletal double pyramids. Many of the masses 
appear to be aggregates of tiny double pyramids which have grown 
together or masses which have formed from many centers. The 
arsenopyrite and pyrite have grown together with very irregular 
boundaries, and particles of the pyrite are buried in the arsenopyrite. 

The arsenopyrite forms small rods which lie both along and across 
the cleavage planes of the muscovite, hence the arsenic mineral is evi- 
dently later than the mica. Arsenopyrite generally exhibits a strong 
tendency to take definite crystal forms when original in a rock, 

1 AABsy by E. £. BarliDgAme A Co., Deader, Colo. 
94174'*— BuU. 470-U U 

Digitized by 



and the lack of definite crystal planes on the aisenopyrite m this 
deposit also shows that it was introduced after the schist was formed. 

In most of the observed granitic masses, and accompanying a 
number of the pegmatitic dikes, arsenopyrite occurs in noticeable 
quantities. As abeady remarked, the quartz veins of the^ region 
are possibly pegmatitic, but no arsenopyrite was noticed near them. 
A white schistose muscovite-quartz rock of varying thickness, which 
is probably a mashed and altered acidic pegmatite or aplite, accom- 
panies the vein. There is also some vein quartz. 

As the arsenopyrite is in immediate association with the crushed 
pegmatite or aplite at the mine and no granite is known in the 
vicinity, it is probable that the arsenopyrite was deposited by solu- 
tions accompanying the intrusion of the acidic rock. 


The plant for the production of white arsenic from the ore is located 
a few feet below the mouth of the adit, and the loaded mine cars are 
run directly to an ore pile in the buildings. From the ore pile the 
rock is run through a Blake crusher, from which it goes to a 10 
by 20 inch Stuyvesant roll; from the roll it goes to a rotary calciner — 
a large iron tube, 50 feet long and 6 feet in diameter, lined with fire 
brick for 30 feet from the furnace, which is fired with wood. The 
charge is treated 45 minutes at a temperature of about 800^ F. 
(427° C). From the calciner all the gases are drawn through a 
chambered flue 7 feet high, 6 feet broad, and 319 feet long, ending 
in a tall stack. At intervals of 6 feet baffles cross the flue alternately 
from each wall to points within 2 feet of the other waU. The alternate 
contraction and expansion and the cooling of the gas current are said 
to settle the arsenious oxide so completely that none reaches the last 
five compartments. In this form the arsenious oxide is a dirty gray 
powder containing sulphiur, iron, and probably other impurities. 
The draft in the flue is governed by an electric fan, controlled by a 
rheostat sensitive to barometric pressure. After a sufficient amoimt 
of crude arsenious oxide has accumulated in the flues, they are 
opened and the oxide is removed by hand and taken to the refining 
furnace. This furnace is a brick reverberatory fired with coke, and 
volatilizes 1,400 pounds of crude arsejiious oxide in two and one-half 
hours. The sulphur remaining with the crude arsenious oxide is 
converted to SO^ and most of the other impurities are left behind as a 
residue. After passing through the calciner the white arsenic is 
caught in a flue similar to that used for obtaining the crude product. 
From the refiner flue the white arsenic is taken by hand to a 32-inch 
Waldron burrstone mill and after being ground it runs to an auto- 
matic weighing and barreling machine. The white arsenic is packed 
in barrels 22 inches tall, with a 19-inch bilge and 17-inch head, holding 

Digitized by 



500 pounds. The barrel itself weighs 35 pounds. The white arsenic 
made is said to have carried 99.975 per cent of AsjO,. 

The scheme of refining is epitoniized on the following flow sheet: 

Ore from mine. 


Ore pile. 


Ore raised to Blake crusher. 


Ore falls to 10 by 20 inch Stuyveeant rolls. 


Ore falls to rotary calciner. 


Arsenic fumes to crude flue. 


Crude arsenious oxide to refining furnace. 


Aisenious oxide fumes to refined flue. 


Befined white arsenic to Waldron burrstone mill. 


Refined white arsenic to automatic weighing and barreling machine. 


White arsenic to market. 

Digitized by 



The principal publications by the United States Geological Survey 
on the rarer metals are those named in the following list. 

These publications, except those to which a price is affixed, can be 
obtained free by applying to the Director, United States Geological 
Survey, Washington, D. C. The priced publications may be pur- 
chased from the Superintendent of Documents, Government Print- 
ing Office, Washington, D. C. No publications on Alaskan occur- 
rences are listed here. 

Bancroft, Howland. Notes on the occiirrence of cinnabar in central western 
Arizona. In Bulletin 430, pp. 151-153. 1910. 

Platinum in southeastern Nevada. In Bulletin 430, pp. 192-199. 1910. 

Notes on tungsten deposits near Deer Park, Washington. In Bulletin 

430, pp. 214-216. 1910. 

Reconnaissance of the ore deposits in northern Yuma County, Arizona. 

BuUetin451. 130 pp. 1911. 

Becker, G. F. Geology of the quicksilver deposits of the Pacific slope, with 
atlas. Monograph XIII. 486 pp. 1888. 12. 

Quicksilver ore deposits. In Mineral Resources U. S. for 1892, pp. 139-168. 

1893. 50c. 

Blake, W. P. Nickel; its ores, distribution, and metallurgy. In Mineral 
Resources U. S. for 1882, pp. 399-420. 1883. 50c. 

Tin ores and deposits. In Mineral Resources U. S. for 1883-84, pp. 

592-640. 1885. 60c. 

BuRCHARD, E. F. Chromic iron ore. In Mineral Resources U. S. for 1909, pt. 1, 
pp. 591-594. 1911. 

Christy, S. B. Quicksilver reduction at New Almaden [Cal.]. In Mineral 
Resources U. S. for 1883-84, pp. 503-536. 1885. 60c. 

Collier, A. J. Chromite or chromic iron ore. In Mineral Resources U. S. for 
1906, pp. 541-542. 1907. |1. 

Day, D. T., and Richards, R. H. Investigations of black sands from placer 
mines. In Bulletin 285, pp. 150-164. 1906. 60c. 

Emmons, S. F. Platinum in copper ores in Wyoming. In Bulletin 213, pp. 94-97. 
1903. 25c. 

Gale, H. S. Camotite in Rio Blanco County, Colorado. In Bulletin 315, pp. 
110-117. 1907. 

Camotite and associated minerals in western Routt County, Colorado. In 

Bulletin 340, pp. 257-262. 

Glenn, W. Chromic iron. In Seventeenth Ann. Rept., pt. 3, pp. 261-273. 1896. 

Digitized by 



Gbaton, L. C. The Carolina tin belt. In Bulletin 200, pp. 188-195. 1905. 40c. 

Reconnaissance of some gold and tin deposits in the southern Appalachians . 

Bulletin 293. 134 pp. 1906. 

Harder, £. G. Some chromite deposits in western and central California. In 
Bulletin 430, pp. 167-183. 1910. 

HssSy F. L. Some molybdenum deposits of Maine, Utah, and California. In Bul- 
letin 340, pp. 231-240. 1908. 

The Arkansas antimony deposits. In Bulletin 340, pp. 241-256. 1908. 

Note on a tungsten-bearing vein near Raymond, California. In Bulletin 

340, p. 271. 1908. 

Minerals of the rare-earth metals at Baringer Hill, Llano County, Texas. 

In Bulletin 340, pp. 28^-294. 1908. 

Tin, tungsten, and tantalum deposits of South Dakota. In Bulletin 380, 

pp. 131-163. 1909. 

Note on a wolframite deposit in the Whetstone Mountains, Arizona. In 

Bulletin 380, pp. 131-163. 1909. 

Arsenic. In Mineral Resources U. S. for 1908, pt. 2, pp. 599-601. 1909. 

Antimony. In Mineral Resources U. S. for 1908, pt. 1, pp. 709-711. 1909. 

Bismuth. In Mineral Resources U. S. for 1908, pt. 1, pp. 713-714. 1909. 

Selenium. In Mineral Resources U. S. for 1908, pt. 1, pp. 715-717. 1909. 

Tellurium. In Mineral Resources U. S. for 1908, pt. 1, pp. 719-720. 1909. 

Tungsten, nickel, cobalt, vanadium, etc. In Mineral Resources U. S. for 

1908, pt. 1, pp. 721-749. 1909. 

Tin. In Mineral Resources U. S. for 1909, pt. 1, pp. 771-779. 1909. 

Hess, F. L., and Graton, L. C. The occurrence and distribution of tin. In Bul- 
letin 260, pp. 161-187. 1905. 40c. 

Hill, J. M. Note on the occurrence of tungsten minerals near Calabasas, Arizona. 
In Bulletin 430, pp. 164-166. 1910. 

HiLLEBRAND, W. F., and Ransoms, F. L. On camotite and associated vanadif- 
erous minerals in western Colorado. In Bulletin 262, pp. 9-31. 1905. 

HiLLEBRAND, W. F., and ScHALLER, W. T. Mercuiy minerals from Terlingua, 
Texas. Bulletin 405. 174 pp. 1909. 

HoBBS, W. H. The old tungsten mine at Trumbull, Connecticut. In Twenty- 
second Ann. Rept., pt. 2, pp. 7-22. 1902. $2.25. 

Tungsten mining at Trumbull, Connecticut. In Bulletin 213, p. 98. 

1903. 25c. 

Ka.y, G. F. Nickel deposits of Nickel Mountain, Oregon. In Bulletin 315, pp. 
120-127. 1907. 50c. 

Kemp, J. F. Geological relations and distribution of platinum and associated 
metals. Bulletin 193. 95 pp. 1902. 30c. 

Lindgren, Waldbmar. Platinum and allied metals. In Mineral Resources U. S. 
for 1909, rt. 1, pp. 595-602. 1911. 

McCaskey, H. D. Quicksilver. In Mineral Resources U. S. for 1909, pt. 1, pp. 
549-560. 1911. 

Packard, R. L. Genesis of nickel ores. In Mineral Resources U. S. for 1892, pp. 
170-177. 1893. 50c. 

Paige, Sidney. Mineral resources of the Llano-Burnet region, Texas, with an 
account of the Pre-Cambrian geology.' Bulletin 450. 103 pp. 1911. 

Richardson, G. B. Tin in the Franklin Mountains, Texas. In Bulletin 285, pp. 
146-149. 1906. 60c. 

Antimony in southern Utah. In Bulletin 340, pp. 253-256. 1908. 

RoLKER, C. M. The production of tin in various parts of the world. In Sixteenth 

Ann. Rept., pt. 3, pp. 458-538. 1895. $1.20. 

Digitized by 



ScHRADER, F. 0. An occuirence of monazite in northern Idaho. In Bulletin 430, 
pp. 184-191. 1910. 

ScHRADER, F. C, and Hill, J. M. Some occurrences of molybdenite in the Santa 
Rita and Pati^nia mountains, Arizona. In Bulletin 430, pp. 154-163. 1910. 

SiEBENTHAL, C. £. Cadmium. In Mineral Resources U. S. for 1909, pt. 1, pp. 
603-604. 1911. 

Sterrett, D. B. Monazite deposits of the Carolinas. In Bulletin 340, pp. 272- 
285. 1908. 

Monazite and zircon. In Mineral Resources U. S. for 1909, pt. 2, pp. 

897-906. 1911. 

Ulke, T. Occurrence of tin ore in North Carolina and Viiginia. In Mineral 
Resources U. S. for 1893, pp. 178-182. 1894. 50c. 

Watson, T. L., and Taber, Stephen. The Virginia rutile deposits. In Bulletin 
430, pp. 200-213. 1910. 

Weed, W. H. The El Paso tilx deposits [Texas]. Bulletin 178. 15 pp. 1901. 5c. 

Tin deposits at El Paso, Tex. In Bulletin 213, pp. 99-102. 1903. 25c. 

Weeks, F. B. Tungsten deposits in the Snake Range, White Pine County, eastern 

Nevada. In Bulletin 340, pp. 263-270. 1908. 

Digitized by 


Iron and Manganese. 



By Charles Butts. 


Li the course of an area! and economic survey of the Bessemer 
quadrangle, Alabama, in 1910, the writer had the opportunity of 
examining a nimiber of ore deposits, chief of which is the noted 
limonite deposit at Shelby, in Shelby County. There is anotlier 
extensive deposit of brown ore southwest of Montevallo, and small 
deposits exist at other points. Stratified hematites also occur in the 
region. The most important of these deposits have been described 
by Henry McCalley * and P. S. Smith.* 


The limonite deposit at Shelby is the most important in the area 
treated here and the only one now being worked. Through the 
interest of Mr. W. W. Jacobs, president, and Mr. Linn W. Searles, 
consulting engineer, of the Shelby Iron Co., the writer is enabled to 
present the following historical statement of operations at Shelby. 
Operations were begun in 1844 to 1846 with the construction of a 
furnace having a daily capacity of 5 tons of cold-blast charcoal pig 
iron, and work has been practically continuous since that time. 

The original furnace was burned in 1853 or 1854 but was soon 
rebuilt by Horace Ware, the owner. The iron made here early 
acquired a high reputation, and as a result of a comparative test of 
Alabama, Georgia, and Teimessee irons made at Columbus, Ga., in 
1852, an order for 1,000 tons was given to Mr. Ware, the largest order 
ever placed in Alabama up to that time. A rolling mill was com- 
pleted in 1860, at which armor plates were made for the Confederate 
Government. The Merrimac was armored with these plates. In 
1862 the name Shelby Iron Co. was adopted. In 1863 a larger fur- 
nace was built, with a daily capacity -of 30 tons. TUs was equipped 

1 Report on the valley regions of Alabama, pt. 2, Oeol. Survey Alabama, 1897, pp. 494-496, 610-512, 
> BalL U. 8. Qeol. Survey No. 315, 1907, pp. 17^174. 


Digitized by 



with warm-blast ovens and was the first furnace to make warm-blast 
charcoal iron in Alabama. In 1865 this furnace was burned at the 
time of Wilson's raid. In 1867 or 1868 the furnace was rehabiUtated 
and in 1869 it was blown in. In 1874 the present No. 2 furnace, 
with a capacity of 75 tons daily, was completed and it has been in 
service ever since except when shut down for repairs. In 1889 the 
old No. 1 furnace was blown out, and later in tJie year the present 
cupola furnace was completed and blown in. It also has a capacity 
of 75 tons daily. 

The area and location of the ore deposit are shown in figure 34. 
The workings have been confined to an area roughly computed at 

100 acres, and the topog- 
raphy of the surroimding 
land does not indicate any 
considerable extension of 
the workable ore. The ore 
deposit occuj:s in and be- 
neath a mound, the top of 
which was originally 100 
feet above the surround- 
ing surface. In a rough 
way the drainage of the 
immediately surrounding 
coimtry radiates from 
this mound. Such rela- 
tions of limonite deposits 
to drainage exist in other 
parts of the State and 
have also been observed 
in central Pennsylvania. 
They suggest that topo- 
graphic conditions have 
had something to do with 
the preservation of the 
lai^er bodies of xmcon- 
soUdated ore-bearing material, and thus indirectly with the origin of 
the ore itself. 

The eastern two-thirds of the ore-bearing area is underlain by 
limestone and the western third possibly by shale, the limestone and 
shale being separated by a fault. The limestone has been uncovered 
at a few points in course of digging for the ore. Where the dip of 
the limestone could be determined it is 20** E. No sbale has been 
exposed in the ore banks and it is not positively known to underlie 
the ore, but outcrops of shale both north and south of the ore war- 
rant the inference that it is under the western part of the deposit. 
The limestone is believed to be of Ordovician C* Lower Silurian") age, 

Digitized by VjOOQIC 






State nporti 



FiQUBB 34. — Sketch map showing location of limonite dopotlt 
at Shelby, Shelby County, Ala. 


heretofore included in the upper part of the Knox dolomite of this 
region, and the shale is the east marginal part of a great mass called 
Montevallo by the State Survey and regarded by the writer as the 
equivalent of the Talladega (Ocoee) slates of the State Survey. 

The ore occurs in two quite different kinds of material sharply 
separated from each other, and the ore of the one differs from that 
of the other. Over most of the ore-bearing area is, or was, a 
layer of compact red loam about 15 feet thick, called the "blanket." 
Underlying the ''blanket" in most of the area is a heterogeneous 
mass of more or less iron-stained clay, sand, and rock fragments. 
On the south margin of the workings, and apparently only there, a 
white and orange sand comes in between the ''blanket" and the clay, 
as shown in the following section: 

Section at $oiUh margin of Shelby foorHnge. 


Loam, red, compact, with lump ore (''blanket") 15 

Sand, pink and white, dightly clayey, with quartz pebbles abun- 
dant •. ^ 6 

Sand like above, but orange-colored , with abundant quarts pebblee . . 6 
Olay, tawny, with ore powder and streaks of slabby ore, with chert 
inclusions, probably residual from limestone 20 

The red loam of the ^'blanket" resembles the red loam of the 
Lafayette formation in other parts of the State. The 12 feet or so 
of sand and pebbles has all the appearance of Cretaceous material 
and probably is such. Test pits south of the workings have encoun- 
tered this sand and gravel. It has been found impracticable to 
utilize the ore where the gravel and sand occur, on account of the 
difficulty of separating the pebbles. The clayey material below, 
composing the great bulk of the deposit, appears to be residual from 
the underlying limestone and shale. In places pinnacles of lime- 
stone project up into the clay to a height of 26 feet or so. 

The ore in the '^ blanket" is designated lump ore. It is scattered 
rather irregularly through the red loam or to some extent aggregated 
into richer bodies having the form of thin lenses. Generally it is in 
small pieces 2 inches or less in diameter, compact and pure, reported 
to average 52 per cent of metallic iron and to yield a ton of ore to 3 or 
4 cubic yards of material. The ore in the underlying clayey mate- 
rial is of all forms occurring in such deposits — small spongy lumps, 
slabby, wavy layers, and concretionary masses. Much of this ore 
contains more or less of impurities, such as inclusions of chert, clay, 
and sand. Some large masses are too sandy for use. All gradations 
occur, down to sandstone composed of detrital sand and fine chert 
fragments, originally occurring loose in the deposit, with just enough 
iron oxide for cement. According to a report of the former super- 
intendent, W. H. Walker, the ore in this part of the deposit runs 45 
per cent iron and the yield is a ton of ore to 10 cubic yards of material. 


zed by Google 


The thickness of the deposit has never been determined, but it is 
known by test pits in the bottom of the deepest workings to be over 
100 feet thick and to contain ore to the greatest depths explored. 

Mr. TiJTin W. Searles, of Birmingham, Ala., states that a recent 
drill hole in the bottom of the old workings, 30 feet below the original 
surface, had reached a depth of 100 feet and passed through 40 feet 
of almost soUd brown ore and the remaining 60 feet through wash 
ore with varying proportions of ore and clay, but all apparently 
minable. These facts are interesting and important in view of the 
apparently approaching exhaustion of the more superficial ore and 
show besides that the original deposit was at least 130 feet thick. 

Most of the ore at the present time appears to be of the fine, brown, 
spongy variety. The richer "blanket" ore has been nearly ex- 
hausted and also apparently the most productive part of the clayey 
deposit just under the " blanket." In previous working the plan has 
been to follow the lead of the richer ore bodies as they were discovered, 
either in the course of excavation or by drilling; consequently the 
area has been deeply trenched in an irregular manner, leaving laige 
masses of undisturbed material between the excavations. The de- 
posit appears to have been worked around the margins about to the 
limit of profitable operation. Future operations will therefore of 
necessity be confined to the unworked material between the old 
workings and to the material of unknown depth still remaining at 
the bottom of the deposit. As stated above, this bottom material 
has been explored to some extent with promising results. 

The ore is all taken out with steam shovel, the ore bodies being 
£j*st located by hand drill in front of the advancing shovel. Ore and 
dirt are taken out together, loaded into tram cars of about one shovel 
or one cubic yard capacity, and conveyed to log washers, by which 
the ore and dirt are separated, with the assistance of hand picking, 
to remove the coarser impurities. 

The following are analyses of ore from the Shelby bank: 

Analyses of iron ore from Shelby ^ Ala. 





Ferric oxWe (FeiOi) 




















72 620 


7 815 

PhOBpharus (P) ]. . .[ 


Almnlna (AliO,) 

MftngAnPflP niciHA (Mn,Oj) ... 

Lime(caoo....:..?^. •.;;::::::::::::::::::::;:::::;::;:::::: 

liamesia (MgO) 

suiphuriS) ; ::' 

Water (HsO) 











Phosphorus In Iron 

1,2. Smith, E. A., Geol. Survey Alabama, Report of progress for 1875, 1876, p. 109. Analyst, 
C. F. Chandler. 

3. Tuomey, M., Blenn. Kept. Alabama Oeol. Survey for 1855, 1858, p. 201. 

4. McCallev, Henry, Report on the valley regions of Alabama, pt. 2, GeoL Survey Alabama, 1897, p. 619. 
Analyses 1, 2, and 3 are also reprinted in HoCaltey's report, p. 519. 

tized by Google 



The following analyses; made in January, 1911, have been fur- 
nished by the company. 

Analyses of limonUefrom the SMhy ore hoTik, 


Silica (BiOi) 

MftTimngwe (Mn).. 











, .09 















These analyses show a somewhat higher percentage of iron and less 
siUca and phosphorus than the brown ores of the Woodstock district. 
The manganese is about the same. 

The character of the pig iron is shown by the following analyses: 

Analyses of pig iron from Shelby furnace. 

Grade of 























































There is enough manganese in the iron to give it toughness, and it 
is all used in the manufacture of car wheels and chilled rolls and for 
special castings. 

Charcoal is the fuel used and is obtained mostly from the sur- 
rounding country. The average consumption is 106.21 bushels of 
charcoal to a ton of iron. The flux at present is obtained from the 
marble quarries in the vicinity of Sylacauga. The furnace burden 
is about as follows: 


Charcoal 2,000 

Ore 4,220 

Flux 810 

The output for the two furnaces is about 25,000 tons a year, and 
the present price (March, 1911) is from $22 a ton up, on the cars at 

Digitized by 




Three miles west of Brierfield is a deposit of brown ore from which 
ore was obtained for the Bibb furnace from the time of its establish- 
ment in 1862 until its abandonment about 1895. The furnace was 
half a mile east of the ore bank and was connected by railroad \Hth 
the bank and with the Southern Railway at Brierfield. The old 
stack is still standing, but the railroad has been torn up. (See sketch 
map, fig. 35.) It is said that iron smelted at the Bibb furnace was 
manufactured into cannon at Selma for use by the Confederate Army 
during the Civil War. At a later date the furnace suppUed iron to a 
nail rnill located at Brierfield. Cut nails were made at this mill, but 
the introduction of wire nails forced it out of business about 1895; 
this compelled the furnace to go out of operation also. The capacity 
of the furnace is reported to have been 45 tons a day, about three times 

that much ore being 

The old ore diggings 
are in the southern 
part of sec. 22 and the 
northern part of sec. 
27, T. 24 N.,R. 11 E. 
They extended over 
an area of about 10 
acres and reached a 
depth estimated at 60 
feet. The ore occurs 
in red or orange-col- 
ored sand or sandy 
clay, containing also 
many chert bowlders 
and much smaller chert debris. The deposit is underlain by Eiiox 
dolomite. At one point in the bottom of the ore pit is a boss of 
dolomite, and not over 200 feet distant on the same level is an expo- 
sure of variegated, crumpled clay that seems clearly of Cretaceous 
age. Apparently in Cretaceous time clay was deposited in the hol- 
lows in the Knox dolomite and subsequently covered by unstratified 
sand and clay, probably derived for the most part from the adjacent 
ridges, which also furnished the intermixed chert dfibris. In this 
heterogeneous mass of material the ore was segregated. According 
to report, no ore occurs in the variegated clay at the bottom. 

The ore appears to be of the same types as in the Shelby bank, 
being in compact lumps near the top and of platy and concretionary 
character below. So far as could be judged from the waUs of the old 
diggings, most of the ore occurs in the top 20 feet. The lump ore 
appears as small lumps aggregated in more or less distinct bands in 


Cretaceous sand 
and day 


^ ^ 


Rome ("Monte- 
vallo'') shale 


FloiTBE 35.— Sketch map showing location of limonite deposit 3 
miles west of Brierfield, Shelby County, Ala. 


zed by Google 


the face of the workings, the bands being probably cross sections of 
lenticular aggregations of ore. As usual with this class of ore, it 
occurs in irregular pockets, and excavation might continue for several 
days without encountering much ore. 

A large area in this locality is covered with Cretaceous or later 
deposits, apparently identical in character with that at the Bibb 
furnace banks and presumably carrying workable ore, evidences of 
which may be seen here and there on the surface. (See sketch map, 
fig. 35.) There are reports of ore in the region immediately southeast 
of the Bibb furnace, and some ore from this locality was supplied 
to the furnace by individuals who hauled it in wagons. 

The ore from the Bibb bank is reported to have yielded about 40 
per cent of iron in the furnace. Analyses of the ore are given below. 

ArutlyseB of iron ore from Bibb furnace bank in sees. 22 and 27 , T. 24 N., R. 11 E.^ 

Ferric oxide (FeiOi) 


Phosphoric acid ( FsO&) 

Oxide of manganese (MnO). 
Metallic Iron O^e) 









a MoOalky, Henry, Report on the valley regions of Alabama, Oeol. Survey Alabama, pt. 2, 1897, p. 484. 

1. An average sample of the ore of the banks in the S W. \ NW. } sec. 27, T. 24 N., R . 11 E. 

2. A compact ore with a slight metallic appearance and with irregular velvety-looking seams. Locality, 
Mechanics' bank. Collected by T. J. Peter, Brierfleld. 

3. Labeled " From hUl opposite Bibb fmnace." Colkwted by T. J.Peter. 

4. A concretionary limonite with the cavities lined with a fibrous limonlte and holding a well-bleached 
white siliceous or cherty rocky material, canying over 97 per cent of silica. 

It may be noted here that west and northwest of the Bibb bank 
for a distance of 4 miles a number of other ore-bearing areas have 
long been known. They are described by E. A. Smith in his report 
of progress for 1875, pages 86-95, and Smith's account is republished 
by McCalley in his report on the valley regions, part 2, pages 488-495. 
One locality in the NW. \ sec. 13, T. 24 N., R. 10 E., was visited by 
the writer. A number of test pits had been recently dug covering 
a considerable area, and ore had been taken out of them which 
appeared to be of about the usual grade. It occurs in Cretaceous 
material. There is clearly a great deal of ore in this general region, 
but it is to be presumed that the deposits are not rich enough in 
iron of a satisfactory grade to compete with such deposits as exist 
in the Woodstock district and the other localities in the State where 
brown ores are being mined. It seems highly probable, however, 
that this general region holds large reserves of workable ore that 
will be exploited as soon as the richer deposits of the State are 
exhausted or greatly depleted. 

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In the NE. i sec. 20 and the NW. i sec. 21, T. 24 N., R. 14 E., 
on property belonging to W. W. Shortridge, of Binningham, are two 
small areas containing high-grade limonite. (See sketch map, fig. 36.) 
Some of the limonite is manganiferous. 

These deposits occur in residual clay from shale classed as the 
Montevallo formation by the Alabama Geological Survey, but 

IfnBMippiaB ChkkamaagaC'Pd- Slates and shalM, 
('* Lower OaziMHU- ham") limestoM Uontcvallo 
n aha]«, of State reports. 

"ssssr ■««& 

Z3 CZ 



Strike and dip Strike of vwtieal PriMpeetpit 

FiouRX 36.— Sketch map showing location of iran-ore and marble deposits soatheast of Calan, Shelby 

County, Ala. 

probably the same as the Talladega (Ocoee) slates of that Survey. 
One patch of the ore lies on the flank of a ridge and the other on top 
of a ridge. Along each of these ridges there is an outcrop of highly 
ferruginous sandstone or lean hematite on opposite sides of a syncline. 
These outcrops converge northward; their relations are shown on the 
sketch map (fig. 36). 

Digitized by VjOOQIC 


The lai^er ore-bearing area, on the north, is 200 to 300 yards 
long by 75 yards or so in width. The patch on top of the ric^e to 
the south is very small. Test pits in these areas show the presence 
of a considerable proportion of high*grade ore in large masses and 
fine particles in the clay. It is believed by those competent to 
judge that this clay carries a large content of wash ore, some of 
which is rich in manganese. No analyses are at hand. It is highly 
probable that the brown ore has been derived from the lean hema- 
tite outcropping on the ridges and dipping under the areas holding 
the limonite. 

Notwithstanding the richness of these deposits the areas are too 
small to be of much value, for they do not contain ore enough to 
warrant building a railroad or installing a plant for mining. The 
deposits are of interest, however, because of their occurrence in an 
area underlain by shale or slate instead of limestone or dolomite. 

Just south of Mosteller, on a ridge in the SW. i sec. 23, T. 22 S., 
R. 1 E., is a small deposit of ore underlain by very cherty Knox 
dolomite. Some good lump ore occurs in a "blanket" of red loam 
similar to that at Shelby. Considerable ore has been taken out, 
having been hauled by wagon to the railroad near by for shipment. 
The ore-bearing area is very small, and below the blanket, which 
is only a few feet thick except on one side, the ore is so full of chert 
fragments as to be worthless. Much of it can be regarded as noth- 
ing more than a chert breccia cemented by limonite. The deposit 
is not commercially important. 

About half a mile south of the Mosteller deposit, near the center 
of the NW. i sec. 6, T. 24 N., R. 16 E., a little ore shows on the 
surface and some small test pits have been dug. There is nothing 
here to indicate the presence of a deposit of conunercial importance. 

About 2 miles northeast of Shelby, in the SE. i sec. 8., T. 22 S., 
R. 1 E., is a small patch of ore-bearing material that has been pros- 
pected. It is of no importance. 

The region included in this discussion has been fully explored for 
ore deposits, and nothing of importance has been discovered outside 
of the occurrences at Shelby and the Bibb furnace. It seems a safe 
conclusion that no other limonite deposits of economic importance 
occur in the region. 


Hematite ore occurs in the rocks which are classed by the Ala- 
bama Geological Survey as Montevallo (Variegated) shale but which 
are equivalent to the Talladega (Ocoee) slates of the State Survey. 
The only deposit of possible value occurs in Columbiana Mountain, 
east of Columbiana, in association with the quartzite beds to which 

Digitized by 



that ridge owes its existence. (See sketch map, fig. 37, p. 226.) 
Reports are in circulation, however, of the existence of an ore bed 
extending southwest of Columbiana in the same slate formation. 
The probable basis for this report is discussed on page 228. 

The rocks of Columbiana Mountain are shale or slate inclosing 
strata of sandstone or quartzite, the whole mass, begioning at the 
lowest quartzite stratum, being some 1,600 feet thick if there is no 
repetition due to faults or folds. A roughly approximate section 
is as follows: 

Section of rocks in Columbiana Mountain. 

[Complied from section west of Leeper's mill on Beeswax Creek, half a mile northwest of Klngdon Chnrdi, 
and flrom section on crest of mountain on road to Mardls Ferry, U miles northeast of Columblanap In the 
SW. i sec 19. T. 21 8., R. 1 E.] 


1. Quartzite 10 

2. Shale, stiff, blue, calcareous (?); ore at base (see p. 227) 180 

3. Quartzite 5 

4. Shale, stiff, blue, calcareous (7); ore at base of this shale on 

Mardis Ferry road and northwsurd (see sections, p. 227) 618 

6. Quartzite, thin bedded 75 

6. Quartzite, thick bedded, conglomeratic 25 

7. Shale (mainly), greenish 85 

8. Ore and shale (see p. 227) 11 

9. Shale with a few thin quartzite layers 300 

10. Quartzite 3 

11. Concealed ; a little shale or shal y sandstone at top 250 

12. Quartzite, conglomeratic 30 

13. Shale, great thickness. 


The part of the section on Beeswax Creek, Nos. 1 to 6, inclusive, 
was measured by the writer; the part on the mountain northeast of 
Columbiana was measured in part by the writer, but some gaps were 
filled in from the section by P. S. Smith,* who studied the section 
along the old road down the east side of the mountain, while the 
writer saw only the section in the newly located road, where the 
rocks are not so fully exposed as in the old road. 

Columbiana Mountain is a curving ridge of elliptical form which 
is well enough delineated by the outcrops of the sandstone strata 
shown on the map (fig. 37). The form of the mountain is due to the 
geologic structure, which is synclinal, with an axis pitching steeply 
to the northeast, so that the strata lie in a basin shaped like the prow 
of a canoe and the outcropping edges necessarily take an elliptical 
outline. Along the western outcrop the rocks dip to the east or 
southeast; on the southeastern outcrop the rocks dip to the north- 

1 The gray iron ores of Talladega County, Ala.: Bull. U. S. Geol. Survey No. 315, 1907, pp. 161>184. 

Digitized by 



Partly inclosed within the ellipse of Columbiana Mountain is 
another ridge of triangular form, lying in sees. 9 and 16, T. 21 S., 
R. 1 E., which, like Columbiana Mountain, is the result of the pres- 
ence of several strata of resistant sandstone or quartzite. The rocks 
of this ridge he in the center of the syncline and are underlain at 
great depth by the rocks of Columbiana Mountain. Ore occurs at 
a number of points in both Columbiana Mountain and the triangular 
ridge, but the only bed that shows any promise of economic im- 
portance Ues close above the quartzite given as Nos. 5 and 6 of the 



("Lower C 

faraiM^ shale 

Ordovicttn age 

Slates and thalee. 

of State reports, 

4r MIbAmM AlTMy 

itS^^ y^ ^ '^*'* ^ 

Bed of ironoce 

Ore pit 

Stiike and dip Strike of vertical 

Qoartate beds, 
Weiener quartzite 
of State reporu 

FioxTBE 37.— Sketch map showing location of hematite ore in Columbiana Mountain, 
Shelby County, Ala. 

section on page 224. This quartzite is shown on the map as a con- 
tinuous outcrop from the fault at a point north of IGngdon Church 
to the northwest comer of sec. 8, T. 21 S., R. 1 E., where it dis- 
appears, apparently by thinning out. The above-mentioned ore 
bed is known only north of the Mardis Ferry road. It has been 
thoroughly prospected for about 2 miles along its outcrop in sees. 7, 
8, and 18, T. 21 S., R. 1 E., and its outcrop in these sections is shown 
on the sketch map (fig. 37). 

04174**— Bull. 470—11 15 

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The ore consists of layers in shale, as shown in the following 

Section of ore in pit on knoll half a mile northeast of NeUon, in the NW, \ sec. 8, 

T. 21 S,, R. 1 E. 


Shale, iwde gray, fiasile, soft 10 

Ore, api)arently of good grade 7 

Ore, low grade 3 

Sandstone 2 

Shale, pale gray, fissile, soft 15 

Sandstone (?}. 

Another pit 50 feet farther north showed about 8 feet of ore. At 
these pits the beds are vertical and strike N. 50° E. On the crest of 
the ridge one-sixth of a mile southeast of Nelson station is a oit at 
which the following section was measured: 

Section of ore in pit one-sixth mile southeast of Nelson station, in western part of sec. 5, 

T. tl 8., R. 1 E. 

Ft. In. 

Shale 12 

Shale, ferruginous, lean ore, worthless 8J 

Ore, probably low grade and worthless 7 

Shale, ferruginous 2 

Ore(?), low grade, probably worthless 11 

Shale, more or less ferruginous 8J 

Ore, low grade, probably worthless 7 

Ore, apparently fair grade 5 

ShsJe, ferruginous 2 4 

Ore, apparently high grade 3 6 

ShaleC?) 10 

Quartzite, conglomeratic 

At this pit the strike is N. 20"* E. and the dip SO"" E. A little over 
a mile southwest of this pit, in the NW. i SE. i sec. 18, T. 21 S., 
R. 1 E., another measurement was obtained as follows: 

Sectum of ore bed at pit in the NW. J SE. J sec. 18, T. 21 8., R. 1 E. 

Shale. Ft. In. 

Ore, fair grade 1 

Shale, with ore streaks up to 2 inches 5 

Ore, fair grade (?) 2 6 

Shale 10 

Ore, bottom not certainly seen 2 

Shsde, ferruginous. 

The strike here is N. 10^ E. and the dip 30° E. On the Mardis 
Ferry road, according to Smith,* this same ore bed is made up of a 
number of thin layers of hematite separated by shale and the ore is 
somewhat quartzose. 

The extent of this bed south of the road and around the syncline 
to the northeast above the underlying quartzite, shown on the map, 

I Smith, p. S., op. dt, p. 174. 

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is unknown. In the Beeswax Creek section^ where the exposure of the 
rocks is unbroken, it is not present above the quartzite, Nos. 5 and 6 
of the section (p. 224). 

On Beeswax Creek a much higher ore bed is exposed, a section of 
which is shown below. 

Section of ore bed on Beeswax Creeks on west side of sec. Sly T. 21 5., R. 1 E. 

Shale, blue, calcareous (7) (No. 2 of seotiou, p. 224). Feet. 

Ore, rounded quartz grains size of clover seed, cemented with iron 

oxide, apparently high in iron 1 

Sandstone, green, with fine quartz grains, as in ore 1 

Shale, blue, ordinary type 12 

Ore, apparently good g^e 1 

Shale 3 

Sandstone, fine grained, ferruginous, lean ore (?^ 3 

Sandstone, conglomeratic (No. 3 of section, p. 224) 5 

At this point the strike is N. 30° E. and the dip 25° NW. On the 
Mardis Ferry road in the SW. i sec 19, T. 21 S., R. 1 E., Smith ^ 
noted the following section: 

Sectvm of ore bed on Mardis Ferry road in the 8W. } see. 19, T. tl S., R. 1 E. (No. 8 

of section, p. 224, • 

Shale. Ft. In. 

Ore 2 

Shale (?) 4 6 

Ore 6 

Shale (?) 1 

Ore 3 

The dip of this bed is 27° E. McCalley^ reports the following 
sections from test pits in the SW. \ sec. 29, T. 21 S., R. 1 E.: 

Sections of ore hedinUstpits in theSW. i sec, 29, T, 21 S., R. 1 E. 

Vo. 1. 

Ft. In. 

Shale, greenish 3 

Ore, red; shales interstratifiod ... 1 2 

Ore, red, compact, about 1 1 

Shale, nearly 2 

Ore, red, compact 11 

Shale 1 

Ore,red 1 3 


Ho. S (40 feet £roa Ho. 1, on lame bed). 

Ft. In. 

Ore, red, very fine; amount visi- 
ble about 7 

Shale, about 3 

Ore, red, and shale; ore phaly 1 6 

Shale; dove and greenish colors. . . 

Ore, red, not very good 1 2 


From the geographic location of these sections it appears that the 
ore bed is stratigraphically considerably below th*e lowest quartzite 
stratum of Columbiana Mountain, No. 12 of the section (p. 224). 
Ore d6bris or float occurs at several points on Columbiana Mountain 
in association with the quartzite strata, but most of such ore appears 

« Smith, P. 8., op. cit., p. 170. 

s ICoCalley, Henry, Report on the valley regions, pt. 2, QeoL Survey Alabama, 1897, p. 511. 

Digitized by 



to be of low grade and does not warrant extended description. At 
some points highly ferruginous quartzite debris occurs at the outcrop 
of one or another stratum of quartzite and evidently is derived from 
the quartzite. Highly ferruginous sandstone occurs also in associa- 
tion with the stratigraphically much higher rocks of the triangular 
ridge in sees. 9 and 16, T. 21 S., R. 1 E. These ore beds clearly occur 
as lenses in the great mass of shales and quartzites of the region. 

Highly ferrugmous fine-grained sandstone or lean hematite occurs 
several miles southwest of Columbiana, near Buxahatchee Creek, in 
the same formation as that of Columbiana Mountain. (See sketch 
map, fig. 37, p. 225.) One occurrence is in sees. 4 and 8, T. 24 N., 
R. 14 E., where a bed of unknown thickness outcrops for a mile or 
so, as shown by the distribution of its d6bris. A bed stratigraphi- 
cally higher occurs in sees. 17, 18, 20, and 21, T. 24 N., R. 14 E. This 
bed Hes along the axis of the great syncline extending northeastward 
through Columbiana Mountain. The axis in this region pitches 
southwestward, so that the outcrops of the rocks on opposite sides 
of the syncline converge northeastward, as shown on the map 
(fig. 37). 

It is the occurrence of these ferruginous sandstones or lean ores 
that has given rise to the reports of ores of supposed value in the 
great area of shales and slates to the southwest of Columbiana, and 
the occurrence of the ore beds at and southwest of Columbiana has 
served as foundation for a rather current though erroneous belief 
that there are continuous ore beds between this region and the beds 
of gray ore at Talladega. Although the Talladega gray ores, the 
ores in Columbiana Mountain, and the lean ores farther southwest 
probably all occur in the same formation, they occur as discontinu- 
ous beds or lenses in the region discussed in this paper. All the ore 
of the shale and quartzite formations in this region is hematite, 
whether in the better grades or in the ferruginous sandstones, some 
of which may rank as lean ore. They are all stratified deposits 
and in some of their aspects resemble Clinton ore. The layers of 
the better ore of Cblumbiana Mountain, such as that of the bed above 
the quartzite (Nos. 5 and 6 of the section on page 224), sections of 
which are given on page 226, are intersected by joints and bedding 
planes which divide the ore into smooth-faced rhombohedral pieces 
generally less than 6 inches in diameter. In the lean ores and fer- 
ruginous sandstones this manner of jointing is less conspicuous. 
The areal extent of any of the ore beds is not known, but as they 
give out along their outcrop when traced far enough, as shown by the 
disappearance of their float or d6bris, it is a reasonable presumption 
that they give out underground also. In other words, the ore beds 
are lenticular deposits. The extent underground depends also on 
their manner of origin — ^whether they are original deposits or have 

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been formed through partial replacement by iron compounds of 
other beds subsequent to their deposition. If the iron is an original 
deposit, the ore beds are likely to have a larger extent than if it is a 
replacement; for replacement to a sufficient extent to form a work- 
able ore bed probably would not occur under the conditions existing in 
this region. 

The only facts bearing on the underground extent of the ores are 
reported by W. H. Walker, former superintendent of the Shelby iron 
works, who says that in a prospect pit driven in for about 30 feet 
the ore layers passed into shale. This might be due either to the 
replacement of shale by ore near the surface or to the accidental 
circumstance that the location of the pit was near the maigiii of a 
lens of ore which feathered out at the depth reached. It was not 
stated whether the ore layers thinned out or passed into shale with- 
out thinning. No prospecting has been carried to a sufficient depth 
to permit a reliable conclusion regarding the persistence of the ore 
beneath the surface. 

Microscopic examinations of thin sections of the ore show it to 
be composed of quartz grains, minute pebbles of the size of clover 
seed, fragments of feldspar, particles of a green mineral that may 
be chlorite, and probably other minerals, all cemented by iron 
oxide. The sections examined do not show whether the iron oxide 
replaces other minerals originally present or whether it was of sedi- 
mentary origin like the inclosing slates. These slates are commonly 
calcareous, and the ore layers may have been originally highly cal- 
careous and the calcareous matter may have been later replaced by 
the iron oxide. 

No recent analyses of the ores from Columbiana Mountain are at 
hand. It is stated by Mr. Walker that analyses by the Shelby Iron 
Co. showed 42 to 43 per cent of metallic iron. The following analyses 
from diflFerent reports of the Alabama Survey probably represent the 
average composition of the ore: 

Analyus of iron ores from Columbiana Mountain.^ 

FeiTic oxide (FoiOt) 



Phosphoric acid (Ps0»).... 


3 0zideOCniOi). 

Metallic iron (Fe). 








47.41 I 








a McCalley, Henryi Report on the vaUey regions, pt. 2, Oeol. Survey Alabama, 1807, p. 512. 

1. Ore from Colnmbiana Mountain. Analyst, J. B. Britton. 

2. Ore from Gohmiblana Mountain. Analyst, C. F. Chandler. 
1875, Geol. Survey Alabama^ 1876, pp. 134, 12S. 

8. Ore from Columbiana Mountain. Tnomey, M., Second Bienn. Kept Geology of Ale 
4. Average sample of ore from pits in the 8 w. } sec. 29, T. 21 8., R. 1 £., dri^ at 100' 
on p. 227.) 

Smith, E. A., Report of progress for 

of Alabama, 1858. p. 80. 
C. (See sections 

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It is not unlikely that the samples of analyses 1 to 3 in the above 
table are from the bed above the quartzite, Nos. 6 and 6 of tho section 
on page 224, the bed prospected so extensively, as described on pages 
225-226. This bed makes the greatest show on the surface by dfibris 
and would be more likely to attract attention than any other. 

A furnace test on a carload of this ore was made at the Shelby iron 
works. According to W. H. Walker, former superintendent of the 
works, the ore was found to be very refractory, its funon requiring a 
veiy high heat. Enough is known about this bed to warrant the 
opinion that it may be a future source of ore of moderate importance, 
but no other bed of which as much can be said is known either in the 
Columbiana region or in the Buxahatchee r^on to the southwest. 

Digitized by 




A number of the principal papers on iron and manganese ores pub- 
lished by the United States Geological Survey or by members of its 
staff are listed below. The Government publications, except those 
to which a price is aflSxed, can be obtained free by applying to the 
Director, United States Geological Survey, Washington, D. C. The 
priced pubUcations may be purchased firom the Superintendent of 
Documents, Government Printing Office, Washington, D. C; the 
folios from either that official or the Director of the Survey. Several 
geologic foUos not given in this list contain descriptions of iron-ore 
deposits of more or less importance. 

Ball, S. H. The Hartville iron ore range, Wyoming. In Bulletin 315, pp. 190- 
205. 1907. 

Titaniferous iron ores of Iron Mountain, Wyoming. In Bulletin 315, 

pp. 206-212. 1907. 

Bancroft, Rowland. Eeconnaiflsance of the ore depoeita in northern Yuma 
County, Ariz. Bulletin 451. 130 pp. 1911. 

Barnes, P. The present technical condition of the steel industry of the Unit^ 
States. Bulletin 25. 85 pp. 18S5. 10c. 

Batlet, W. S. The Menominee iron-bearing district of Michigan. Monograph 
XL VI. 513 pp. 1904. 11.75. 

Batley, W. S., and others. Passaic folio (No. 157), Geol. Atlafl U. S. 1908. 25c. 

BiRKiNBiNE, J. The production of iron ores in various parts of the world. In 
Sixteenth Ann. Kept., pt. 3, pp. 21-218. 1894. |1.20. 

Boutwell, J. M. Iron ores in the Uinta Mountains, Utah. In Bulletin 225, pp. 
221-228. 1904. 35c. 

BuRCHARD, E. F. The iron ores of the Brookwood district, Alabama. In Bulletin 
260, pp. 321-334. 1905. 40c. 

^ The Clinton or red ores of the Birmingham district. In Bulletin 315, pp. 

130-151. 1907. 

The brown ores of the Ruasellville district, Alabama. In Bulletin 315, 

pp. 152-160, 1907. 

The Clinton iron ore deposits in Alabama. In Trans. Am. Inst. Min. Eng., 

vol. 39, 1908, pp. 997-1055. 

An estimate of the tonnage of available Clinton iron ore in the Birmingham 

district, Alabama. In Bulletin 340, pp. 308-317. 1908. 

Tonnage estimates of Clinton iron ore in the Chattanooga region of Tennes- 

jee, Georgia, and Alabama. In Bulletin 380, pp. 169-187. 1909. 

Iron ore, pig iron, and steel. In Mineral Reeourcee U. S. for 1909, pt. 1, 

pp. 71-99. 1911. 

Manganeseore. In Mineral Resources U.S. for 1909, pt.l, pp. 107-119. 1911. 


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BuBOHARD, E. F., Butts, Chablbs, and Eckel, E. 0. Iron ores, fuels, and fluxes 
of the Birmingham district, Alabama. Bulletin 400. 204 pp. 1910. 

Butts, Charles. Mineral resources of the Elttanning and Rural Valley quadran- 
gles, Pennsylvania. Bulletin 279. 198 pp. 1906. 

Clements, J. M. The Vermilion iron-beaiing district of Minnesota. Monograph 
XLV. 463 pp. 1903. $3.50. 

Clements, J. M., Smyth, H. L., Batlbt, W. S., and Van Hise, C. R. The Crystal 
Falls iron-bearing district of Michigan, In Nineteenth Ann. Rept., pt. 3, pp. 1-157. 
1898. 12^5. 

The Crystal Falls iron-bearing district of Michigan. Monograph XXXVI. 

612 pp. 1899. $2. 

DiLLER, J. S. Iron ores of the Redding quadrangle, California. In Bulletin 213, 
pp. 219-220, 1903. 25c. 

So-called iron ore near Portland, Oreg. In Bulletin 260, pp. 343-347. 

1905. 40c. 

Eckel, E. C. Utilization of iron and steel slags. In Bulletin 213, pp. 221-231. 
1903. 25c. 

Iron ores of the United States. In Bulletin 260, pp. 317-320. 1905. 40c. 

Limonite deposits of eastern New York and western New England. In 

Bulletin 260, pp. 335-342. 1905. 40c. 

Iron ores of northeastern Texas. In Bulletin 260, pp. 348-354. 1905. 40c. 

The Clinton hematite. InEng.andMin. Jour., vol. 79, pp. 897-^98. 1905. 

The iron industry of Texas, present and prospective. In Iron Age, vol. 

76, pp. 478-479. 1905. 

The Clinton or red ores of northern Alabama. In Bulletin 285, pp. 172- 

179. 1906. 60c. 

The Oriskany and Clinton iron ores of Virginia. In Bulletin 285, pp. 

183-189. 1906. 

Habder, E. C. Manganese deposits of the United States; with sections on foreign 
deposits, chemistry, and uses. Bulletin 427. 208 pp. 1910. 

The Taylor Peak and Whitepine iron-ore deposits, Colorado. In Bulletin 

380, pp. 188-198. 1909. 

The iron ores of the Appalachian region in Virginia. In Bulletin 380, pp. 

21&-254. 1909. 

Manganese deposits of the United States. In Bulletin 380, pp. 255-277, 


Some iron ores of western and central California. In Bulletin 430, pp. 

219-227. 1910. 

Iron ores near Dayton, Nev. In Bulletin 430, pp. 240-246. 1910. 

Deposits of brown iron ore near Dillsburg, York County, Pa. In Bulletin 

430, pp. 250-255. 1910. 

Harder, E. C, and Rich, J. L. The Iron Age iron-ore deposit near Dale, San 
Bernardino County, Cal. In Bulletin 430, pp. 228-239. 1910. 

Hayes, C. W. Geological relations of the iron ores in the Cartersville district, 
Georgia. In Trans. Am. Inst. Min. Eng., vol. 30, pp. 403-419. 1901. 

Manganese ores of the Cartenville district, Ge(»gia. In Bulletin 213, 

p. 232. 1903. 25c. 

Iron ores of the United States. In Bulletin 394, pp. 70-113. 1909. 

Hayes, C. W., and Eckel, E. C. Iron ores of the Cartersville district, Georgia. 

fa Bulletin 213, pp. 233-242. 1903. 25c. 

HoLDEN, R. J. The brown ores of the New Rivep*Cripple Creek district, Virginia. 
rttBulletin285, pp. 190-193. 1906. 60c. 

Irving, R. D., and Van Hise, C. R. The Penokee iron-bearing series of Michigan 
a(ii^%isconsin. In Tenth Ann. Rept., pt. 1, pp. 341-507. 1889. $2.35. 

Digitized by 



I&YiNO, R. D., and Van Hise, C. R. The Penokee iron-bearing series of Michigan 
and Wisconsin. Monograph XIX. 534 pp. 1892. 11.70. 

KsiTH, Abthub. Iron-ore deposits of the Cranberry district, North Carolina- 
Tennessee. In Bulletin 213, pp. 243-246. 1903. 26c. 

KemP| J. F. The titaniferous iron ores of the Adirondacks [N. Y.]. In Nineteenth 
Ann. Kept., pt. 3, pp. 377-422. 1899. $2.25. 

KiNBLB, £. M. The iron ores of Bath County, Ey. In Bulletin 285, pp. 180-182. 

Leith, C. K. The Mesabi iron-bearing diitrict of Minnesota. Monograph XLIII. 
316 pp. 1903. 11.50. 

Geologic work in the Lake Superior iron district during 1902. In Bulletin 

213, pp. 247-250. 1903. 25c. 

The Lake Superior mining region during 1903. In Bulletin 225, pp. 

21£k220. 1904. 35c. 

Iron ores in southern Utah. In Bulletin 225, pp. 229-237. 1904. 35c. 

Genesis of the Lake Superior iron ores. In Econ. Geology, vol. 1, pp. 

47-66. 1905. 

Iron ores of the western United States and British Columbia. In Bulletin 

285, pp. 194-200. 1906. 

The geology of the Cuyima iron range, Minnesota. In Econ. Geology, 

voL 2, pp. 145-152. 1907. 

Iron ore reserves. In Econ. Geology, vol. 1, pp. 360-368. 1906. 

A summary of Lake Su]>erior geology with special reference to recent 

studies of the iron-bearing series. In Trans. Am. Inst. Min. Eng., vol. 35, pp. 454-507. 

Lefth, ex., and Habder, E. C. The iron ores of the Iron Springs district, south- 
em Utah. Bulletin 338. 102 pp. 1908. 

Paige, Sidney. The Hanover iron-ore deposits, New Mexico. In Bulletin 380, 
pp. 199-214. 1909. 

Preliminary report on pre-Cambrian geology and iron ores of Llano County, 

Tex. In Bulletin 430, pp. 256-268. IPIO. 

Mineral resources of the Llano-Burnet region, Texas, with an accoimt of 

the pre-Cambrian geology. Bulletin 450. 102 pp. 1911. 

Phalen, W. C. Iron ores near Ellijay, Ga. In Bulletin 340, pp. 330-334. 1908. 

Origin and occurrence of certain iron ores in northeastern Kentucky In 

Econ. Geology, vol. 7, 1906. 

Economic geology of the Kenova quadrangle (Ky .-Ohio-W. Va.) . Bulletin 

349. 158 pp. 1908. 

SMrrH, G. 0., and Wilus, Bailet. The Clealum iron ores, Washington. In Trans. 
Am. Inst. Min. Eng., vol. 30, pp. 356-366. 1901. 

Smith, P. S. The gray iron ores of Talladega County, Ala. In Bulletin 315, 
pp. 161-184. 1907. 

Spencer, A. C. The iron ores of Santiago, Cuba. In Eng. and Min. Jour., vol. 72, 
pp. 633-634. 1901. 

Manganese deposits of Santiago, Cuba. In Bulletin 213, pp. 251-255. 

1903. 25c. 

Magnetite deposits of the Cornwall type in Berks and liobanon counties, 

In Bulletin 315, pp. 18^189. 1907. 

Three deposits of iron ore in Cuba. In Bulletin 340, pp. 318-329. 1908. 

Magnetite deposits of the Cornwall type in Pennsylvania. Bulletin 369. 

102 pp. 1908. 

The Jauss iron mine, POlsbuig, Pa. In Bulletin 430, pp. 247-249. 1910. 

Spencer, A. C, and others. Franklin Furnace folio (No. 161), Geol. Atlas U. S. 

1908. 25c. 

Digitized by 



Swank, J. M. Iron and steel and allied industries in all countries. In Eighteenth 
Ann. Kept., pt. 5, pp. 51-140. 1896. 

Van.Hise, C. R. The iron-ore deposits of the Lake Superior region. In Twenty- 
first Ann. Rept., pt. 3, pp. 305-434. 1901. 

Van Hise, C. R., and Bayley, W. S. Menominee special folio (No. 62), Geol. 
Atlas U.S. 1900. 25c. 

Van Hise, C. R., and LsrrH, C. K. The geology of the Lake Superior region. 
Monograph LIl. 626 pp. 1911. Price not yet fixed. 

Van Hise, C. R., Bayley, W. S., and Smyth, H. L. Preliminary report on the 
Marquette iron-bearing district of Michigan. In Fifteenth Ann. Rept., pp. 477-650. 

The Marquette iron-bearing district of Michigan, with atlas. Monograph 

XXVIII. 608 pp. 1897. $5.75. 

Wolff, J. E. Zinc and manganese deposits of Franklin Furnace, N.J. In Bulle- 
tin 213, pp. 214-217. 1903. 25c. 

Digitized by 


Aluminum Ores. 



The following' reports published by the Survey or by members of 
its staff contain data on the occurrence of aluminum ores and on the 
metallurgy and uses of aluminum. The Govenmient publications, 
except those to which a price is aflBxed, can be obtained free by 
applying to the Director, U. S. Geological Survey, Washington, D. C. 
The priced publications may be purchased from the Superintendent 
of Documents, Government Printing Office, Washington, D. C. ; the 
foUo from either that official or the Director of the Survey. 

BuscHABD, E. F. Bauxite and aluminum. In Mineral Resources U. S. for 1906, 
pp. 501-510. 1907. 50c. 

Canby, H. S. The cryolite of Greenland. In Nineteenth Ann. Kept., pt. 6, 
pp. 615-617. 1898. 

Hates, C. W. Bauxite. In Mineral Reaources U. S. for 1893, pp. 159-167. 
1894. 50c. 

The geological relationa of the southern Appalachian bauxite deposits. 

In Trans. Am. Inst. Min. Eng., vol. 24, pp. 243-254. 1895. 

Bauxite. In Sixteenth Ann. Rept., pt. 3, pp. 547-597. 1895. $1.20. 

The Arkansas bauxite deposifa. In Twenty-first Ann. Rept., pt. 3, pp. 

435-472. 1901. 

Bauxite in Rome quadrangle, Georgia-Alabama. Geol. Atlas U. S., folio 

78, p. 6. 1902. 25c. 

The Gila River alum deposits. In Bulletin 315, pp. 215-223. 1907. 

Hunt, A. E. In Mineral Resources U. S. for 1892, pp. 227-254. 1893. 50c. 
Packard, R. L. Aluminum and bauxite. In Mineral Resources U. S. for 1891, 

pp. 147-163. 1892. 50c. 

Aluminum. In Sixteenth Ann. Rept., pt. 3, pp. 53^-546. 1895. $1.20. 

Phalen, W. C. Bauxite and aliuninum. In Mineral Resources U. S. for 1907, 

pt. 1, pp. 693-705. 1908. $1.00. 

Bauxite and aluminum. In Mineral Resources U. S. for 1909, pt. 1, pp 

561-572. 1911. 

ScHNATTEBBEGE, 0. 0. Alumjnum and bauxite [in 1904]. In Mineral Resources 
U. S. for 1904, pp. 285-294. 1905. 50c. 

Spubb, J. E. Alum deposits near Silver Peak, Esmeralda County, Nev. In Bul- 
letin 225, pp. 501-502. 1904. 35c. 

Struthebs, J. Aluminum and bauxite [in 1903]. In Mineral Resources U. S. for 
1903, pp. 265-280. 1904. 70c. 

Digitized by 




The following list comprises the more important papers relative to 
asphalt published by the United States Geological Survey or by 
members of its staff. The Government publications, except those 
to which a price is afl^ed, can be obtained free by applying to the 
Director, U. S. Geological Survey, Washington, D. C. The priced 
publications may be purchased from the Superintendent of Docu- 
ments, Government Printing OflBce, Washington, D. C, 

Anderson, Robert. An occurrence of asphaltite in noitheafitem Nevada. In 
BuUetin 380, pp. 28a-285. 1909. 

BouTWELL, J. M. Oil and asphalt prospects in Salt Lake basin, Utah. In Bul- 
letin 260, pp. 468-479. 1905. 40c. 

Day,D.T. Asphalt. In Mineral Resources U.S. for 1909, pt. 2, pp. 731-734. 1911. 

Day, W. C. The coal and pitch coal of the Newport mine, Or^on. In Nine- 
teenth Ann. Rept., pt. 3, pp. 370-376. 1899. |2.25. 

Eldridoe, 6. H. The uintaite (gilsonite) deposits of Utah. In Seventeenth 
Ann. Rept., pt. 1, pp. 909-949. 1896. 

The asphalt and bituminous rock deposits of the United States. In 

Twentynaecond Ann. Rept., pt. 1, pp. 209-452. 1901. 

Origin and distribution of asphalt and bituminous-rock deposits in the 

United States. In Bulletin 213, pp. 296-^5. 1903. 25c. 

Kates, C. W. Asphalt deposits of Pike County, Ark. In Bulletin 213, pp. 
353-355. 1903. 25c. 

Tapf, J. A. Albertite-like asphalt in the Choctaw Nation, Indian Territory. 
Am. Jour. Sci., 4th ser., vol. 8, pp. 219-224. 1899. 

Description of the unleased sQgr^;ated asphalt lands in the Chickasaw 

Nation, Indian Territory. U. S. Dept. Interior, Circular 6. 14 pp. 1904, 

Grahamite deposits of southeastern Oklahoma. In Bulletin 380, pp. 

286-297. 1909. 

Taff, J. A., and Smith, C. D. Ozokerite deposits in Utah. In Bulletin 285, pp. 
369-372. 1906. 60c. 

Vauqhan, T. W. The asphalt deposits of western Texas. In Eighteenth Ann. 
Rept., pt. 5, pp. 930-935. 1897. 


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Structural Materials. 



By Charles Butts. 

About 3} miles a little south of east of Calera, Ala., is an outcrop 
of marble which is attracting some attention. The deposit was 
noted and described by McCaUey,* and in 1910 was visited by E. A. 
Smith, State geologist of Alabama, to whom the writer is indebted 
for information concerning one of the exposures. Li 1910 the 
deposit was also examined at one point by the writer. 

The exposure examined by the writer is one-fourth of a mile south 
of Buxahatchee Creek, in the NW. i NE. i sec. 8, T. 24 N., R. 14 E., 
on property belonging to J. S. Evans, of Calera. (See sketch map, 
fig. 36, p. 222.) It is easily reached by wagon road from Calera. The 
exposure is on a steep bank near the head of a ravine opening into 
Buxahatchee Valley. A thickness of about 25 feet of marble is 
exposed for 50 feet along the side of the ravine. Below is an approxi- 
mate section showing the stratigraphic relations of the marble. 

Section in ravine Si miles southeait of Calera. 

Sandstone, highly femiginous (lean ore?) 20± 

Shale, weathers yellowish-green 20± 

Marble, thick-bedded, fine-grained, variegated 25db 

Sandstone (quartzite?) coane, with quartz veins 50± 

The sandstone at the base of the section can be followed north into 
the NW. } sec. 4, T. 24 N., R. 14 E., as shown in figure 36. North 

1 McCaUey, Henry, Report on the valley regions of Alabama, pt. 2, QeoL Survey Alabama, 1897, pp 


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of Buxahatchee it makes a high ridge, which is a good marker for 
the outcrop of the marble. 

In the bed of Buxahatchee Creek the sandstone dips 20° to 25^ 
E., and the overlying ferruginous sandstone dips 10° to 15° E. A 
quarter of a mile farther east, however, the dip becomes 40° to 60° E. 

The geologic formation in which the marble occurs was classified 
as Montevallo (Lower Cambrian) by the Alabama Geological Survey. 
The writer concludes that these rocks are the same as those mapped 
by the Alabama Survey as Talladega (Ocoee) slates, which he thinks 
may include the metamorphosed equivalents of the Rome C Monte- 
vallo'') formation. The State geologist, E. A. Smith, informs the 
writer that he has long entertained tliis view of the equivalency of 
the ''Montevallo'* in this section with the ''Talladega." 

The marble is thick bedded, the layers being 3 to 4 feet thick. 
They are cut by joints that divide them into blocks of considerable 
size, and it seems probable that under good cover even larger blocks 
would exist. The dimensions of slabs or blocks that could be 
obtained would have to be determined by tests involving excava- 
tion and the actual working of representative samples of the rock. 
The rock is very fine grained and takes a high poUsh. Part of the 
layers are gray and part are variegated with deep red and pale pink, 
the whole stratum being composed perhaps of one-half of each kind. 
The color is due to a coating of iron oxide on the limestone grains. 
The variegated layers appear to prevail in the upper portion, the 
gray layers below. The rock is traversed by many white and bluish- 
gray calcite veins, and here and there by thin stringers of small 
quartz grains. The variegation gives to the rock a highly orna- 
mental effect when polished, and it would appear to possess superior 
qualities for decorative purposes. 

There is another exposure of this marble about 1^ miles northeast 
of the one just described, in the NE. J NW. i sec. 4, T. 24 N., R. 14 E., 
on land owned by J. W. Miller. For data concerning the marble at this 
point the writer is indebted to E. A. Smith, who says: "It shows 
a thickness of some 20 feet or more of varying shades of pink, choco- 
late, and red colors, alternating with white, sometimes in distinct 
bands, in some parts of rather uniform pink shade. " 

It is assumed that the stratum is continuous between the Evans 
and Miller properties, but no exposures are reported between them. 
The topography is such that a considerable body of marble could be 
obtained in an open-cut quarry, but ultimately the rock would have 
to be mined. 

The outcrop on the Evans property is easily accessible to the 
Louisville & Nashville Railroad, about 2 miles distant, as shown 
on the sketch map. 

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Whether the marble could be exploited with profit is a question 
that would need careful consideration. Competition in the marble 
industry is great, and it would not be easy to establish a new enter- 
prise in that line on a paying basis except under especially favor- 
able circimistances, as has been shown by experience in other parts of 
the country in the case of marble of apparently superior quaUty 
for structural or decorative use. 

Digitized by 




By T. Nelson Dale. 


The granites and granite quarries of Milford, Quincy, Rockport, 
and Becket, Mass., were described in a former bulletin of the Survey.* 
In June, 1910, the remaining active granite quarries of the State were 
visited and the results of these supplementary studies are here given. 
The treatment of the subject is both scientific and economic, as it 
was in that bulletin and in BuUetins 313, 404, 430, and 484, on the 
other New England granites. 

The following scale of shades and texture has been used in all 
these papers. Shades: Very dark gray (Quincy ''extra dark"); 
dark gray (Barre and Quincy *'dark"); medium gray (Concord); 
medium to light gray (HaUowell); light gray (Barre ''light"); very 
light gray (North Jay and Dummerston "white"); white, mottled 
with gray (Bethel). Textures: Coarse, with feldspars over 0.4 inch 
in diameter; medium, with feldspars under 0.4 inch and over 0.2 
inch; fine, with feldspars under 0.2 inch; very fine, with feldspars 
under 0.1 inch. 

As in the bulletins named, the number of each specimen described 
to which that of one or more thin sections correspond is given so 
that the descriptions can be verified by consulting the collections at 
the National Museum. 

All the "granites" here described, as well as the others of Massa- 
chusetts described in Bulletin 354, are commercially classified and sci- 
entifically determined in the table on pages 286-287, which is therefore 
complete for this State. The total number of quarries described is 88. 
Quarries producing only paving, underpinning, or crushed stone 
have been excluded, but the felsite quarry of Revere has been 
included, although it is not entered in the table. 

1 Dale, T. N., The chief commercia] granites ofHiffassachusetts, New Hampshire, and Rhode Island: Bull. 
U. 8. Qeol. Survey No. 354, 1908, pp. 90-liL 


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Digitized by ^ 

Digitized by 



The word '^ granite '' in the title is used in its commercial sense and 
embraces a variety of igneous rocks. The local or trade names of 
the granites used in this paper have no significance as geologic 
formation names. 

The elementary facts as to the origin, composition, physical 
properties, texture, and structure of granite, together with a sum- 
mary of the methods of classifying, testing, and quarrying it, will be 
found in a form intended for general readers in Bulletin 354, pages 
9-72. The definition of the mineral composition of granite given 
there (p. 11) should be revised so as to make the second or plagio- 
clase feldspar include either one containing soda and lime, as in most 
granites, or one containing soda, as in some of the granites described 
in this paper. 

This paper concludes the writer's work on the commercial granites 
of New England. It contains two petrographic determinations con- 
tributed by Dr. Whitman Cross, of the United States Geological 


The quarries to be described are in the towns of Dartmouth, Fall 
River, and New Bedford, Bristol County; Lynnfield and Peabody, 
Essex County; Monson, Hampden County; Pelham, Hampsliire 
County; Acton, Groton, Westford, and Townsend, Middlesex County; 
Wrentham, Norfolk County; Brockton and Hingham, Plymouth 
County; Revere, Suffolk County; and Fitchburg, Leominster, and 
Uxbridge, Worcester County. The distribution of all the granite- 
quarrying centers of the State is shown on the map (PL V). 


The "granites" of these 42 quarries fall into 14 petrographic 
groups: Biotite granite gneiss (Uxbridge, Pelham); biotite granite, 
gneissoid (Fall River); biotite-muscovite granite, gneissoid (Dart- 
mouth, New Bedford); muscovite-biotite granite gneiss (Groton, 
Oak Hill-, Westford, Fitchburg); biotite-quartz monzonite (Town- 
send) ; biotite-quartz monzonite gneiss (Monson) ; muscovite-biotite- 
quartz monzonite gneiss (Snake Meadow Hill, Westford); biotite- 
muscovite-quartz monzonite gneiss (Acton); hornblende granite 
(Wrentham); homblende-augite granite (Lynnfield, Peabody); bio- 
tite-homblende (or altered augite-homblende) porphyritic granite 
(Brockton); mica diorite (Leominster); apUte (Hingham). 


At 12 of these quarries matters of special geologic interest were 
noted. These follow under various headings* 

94174°— BuU. 470— U ^16 

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The muscovite-biotite granite gneiss of the Rafferty quarry, in 
Groton (p. 264), contains several inclusions, the largest of which, 
triangular in outline, measures 30 feet on one side and 8 feet on 
another. This rock (specimen D, XXX, 100, a) is a dark-gray 
biotite granite gneiss with porphyritic feldspars up to 0.6 inch. Its 
quartz is granulated like that of the inclosing gneiss. Both gneisses 
are crossed by a pegmatite dike, and apUte occurs also in both. 

The muscovite-biotite-quartz monzonite gneiss of the Palmer 
quarry, in Westford (p. 271), has a lenticular inclusion, 3 feet by 3 
inches, of very fine grained, evenly foliated quartz-biotite schist with 
some cloudy particles which may be much kaolinized feldspar; also a 
little muscovite and zoisite. This rock may be of sedimentary origin. 
The gneiss at the Oak Hill quarry, in the same town (p. 267), also 
contains small dark finely banded inclusions. 

The quartz monzonite of Barker Hill, in West Townsend (p. 273), 
has inclusions up to 4 feet across of a fine-grained biotite gneiss, 
probably a quartz-mica diorite gneiss like those in the quartz monzo- 
nite of the O'Rourke quarry, in Brookline, N. H., about 5 miles to 
the northeast.* 

The quartz monzonite gneiss of the McCarthy quarry, in North 
Acton (p. 263), is in contact with a very dark grayish, fine textured, 
finely banded, and pegmatized quartz-mica diorite gneiss with oligo- 
clase (specimen D, XXX, 112, b). Within a few feet of the contact 
is an inclusion of the diorite gneiss 


The gneissoid biotite granite of the Savoie quarry, in Fall River 
(p. 252), is crossed by two aplite dikes. One (specimen D, XXX, 
118, a), 10 feet wide, is of light pinkish-gray color and fine, even- 
grained texture. Its second feldspar is albite (soda feldspar), some- 
what micasized and epidotized. Its biotite is chloritized. The other 
(specimen D, XXX, 118, b), up to 2 feet thick, is of dark brownish- 
gray color and semiporphyritic texture, its smaller particles generally 
arranged about the larger. Its second feldspar is also albite. 

The biotite granite gneiss of the Blanchard quarry, in Uxbridge 
(p. 283), has aplite dikes up to 3 feet thick. 

The muscovite-biotite granite gneiss of the Oak Hill quarry, in 
Westford (p. 267), has whitish apUte dikes with longitudinal bands 
of black tourmaline 0.2 inch wide. 

A very unusual dike of aplite crosses the mica diorite of the Leavitt 
quarry, in Leominster (p. 283). (See fig. 38.) It is of light-gray and 
bluish-gray color. Its broadest part consists of over 150 meandering 

1 See BuU. U. S. Geol. Survey No. 430, 1910, pp. 347, 361. 

Digitized by 




parallel bands of these alternating shades (specimens D, XXX, 110, 
b, c), many of them bordered with microscopic prisms of black tour- 
maline with their main axis across the band. The meanderings of 
these bands resemble the plications of a metamorphic stratified rock. 
The aplite contains here and there clear feldspars up to an inch long. 
In thin section it resembles a quartz monzonite, its constituents, in 
descending order of abundance, being oligoclase-albite, quartz, 
microcline, and black tourmaline in minute prisms. The accessory 
minerals are apatite in needles and particles (abundant), pyrite, 
garnet, and flakes of muscovite (rare). The yellowish tinge of some 
of the bands is probably due to the oxidation of the pyrite. A few 
of the bands are pegmatite without tourmaline but with biotite, a 
little muscovite, and ilmenite ( i) surrounded by leucoxene. 

The banding of this aplite dike may be ascribed to a gradual en- 
largement of the fissure and the deposition of aplite on either side, 
as in banded mineral veins. 

The meandering or plication of ^^-^ ^^^ " ^^ 

the bands and the transverse 
orientation of the tourmaline 
prisms are possibly due to one 
cause. Other smaller dikes of 
aplite are parallel to this one 
and some of aplite and of peg- 
matite intersect the main dike. 

Finally should be mentioned 
the considerable area of pyri- 
tiferous aplite quarried in Hing- 
ham (p. 276). • This is of light, 

slightly greenish-gray color and Fioubb SS.— Approximate horizontal sectloD of banded 

scarcely developed sheet struc- ^^ ^^« ^ ^^^»'*' ^*^^" ^^^^' Leominster. 
ture but with many headings 

showing rusty faces from the limonitization of the pyrite. This 
rock also resembles a quartz monzonite, with these constituents in 
descending order of abundance: Oligoclase-albite, quartz, micro- 
cline, and very little biotite mostly chloritized and associated with 
epidote. The accessory minerals are pyrite and magnetite. As the 
stone is extremely hard its percentage of quartz must be high. 


Several interesting basic dikes were noted. 

The elongated porphyritic biotite granite gneiss of the Blanchard 
quarry, in Uxbridge (p. 283), is cut by an amphibolite dike up to 18 
inches thick, the schistosity of which strikes at an angle of 33*^ with 
that of the inclosing gneiss. This dike consists of feather-rimmed 
crystals of hornblende up to an inch in length in a matrix of biotite 

Digitized by 



with interspersed quaxtz grains and minute slender crystals or strings 
of lenses of zoisite. In places, however, along the edges the matrix 
is of quartz, biotite, epidote, and oUgoclase-andesine. The dike was 
originally a porphyritic mica diorite. 

At the Sullivan quarries, near New Bedford (p. 253), is an interesting 
complex of dikes of various sorts and ages whose courses are shown 
in figure 39. The rock is a slightly gneissoid biotite-muscovite granite 
of light pinkish gray color. The central dike A, with northeast 
course and up to a foot thick, is a dark-greenish chlorite schist (speci- 
men D, XXX, 121, c) consisting of chlorite, probably after horn- 
blende, IQ parallel arrangement, micasized plagioclase, quartz, and 
microcline. Its accessory minerals are pyrite, magnetite, purple 
fluorite, apatite, and biotite. Secondary: Epidote, carbonate, and 
hematite from the magnetite. This dike was evidently originally a 
diorite. Dike B on the south wall, with a N. 70^ E. course and a dip 

of 60"* N. 20° W., over 2 
^ «" feet thick, is a dark-grayish 

mica diorite schist (speci- 
men 121, d), consisting, in 
descending order of abim- 
dance, of andesine, biotite, 
epidote, and muscovite. 
This was originally a mica 
diorite. Dike C, on the 
north wall, with a N. 60*" E. 
course, and vertical dip, up 
to 3 feet thick, is a black, 
fine-grained mica diorite 
schist (specimen 121, f), 
consisting, in descendiog 
order of abundance, of biotite, oligoclase, microcline, quartz, and epi- 
dote. This also was originally a mica diorite. It differs from dike B 
in being more micaceous and in containing no muscovite. The edge of 
this dike (specimen 121, g), for a thickness of a few inches, consists of 
brecciated grayish feldspars up to 0.3 inch in diameter in a matrix 
of biotite. At the extreme edge this breccia passes into a mass of 
the same feldspar with a Uttle quartz and still less biotite. The more 
glassy rim of the dike resisted the pressure which brecciated its inner 
border and converted its central part into a schist. Dike D, near 
the west wall, with a northwest course and steep dip, 3 inches thick, 
is p^matite. It intersects the central chlorite schist (diorite) dike. 
Finally, dike E, on the west wall, with a N. 10*^ E. course, up to 2 
feet thick, is a diabase (specimen 121, e) with ophitic texture, con- 
sisting, in descending order of abundance, of andesine, pyroxene, 


9.— Structure and dikes at Sullivan quarries. New 
Bedford, Mass. 

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serpentine (probably after olivine), and magnetite or ilmenite with a 
little carbonate aiid biotite. This was presumably an oUvine diabase. 

The evidence from these dikes shows that the granite was injected 
with dikes of diorite and mica diorite. Later it and the dikes w^ere 
crossed by pegmatite. After dynamic metamorphism had altered 
the diorites to schists they were traversed by a diabase dike in which 
the only change has been the serpentinization of the olivine and the 
micasization of the andesine.^ 

As there is a marked difference between the schistosity of the diorite 
and that of the granite, which is but slightly gneissoid, it is evident 
that the dynamic metamorphism which brought about the schistosity 
of the dikes was produced by the pressure of their granite walls. The 
same thing was noticed as to certain dikes in the granites of Milford, 
Mass., and has also been recently observed by geologists of the British 
Geological Survey in Ross-shire, Scotland.* 

Another basic dike noticed in these quarries was an altered but 
not metamorphosed lamprophyre, in the gneissoid biotite granite of 
the Seattle & Wilcox quarry, at Fall River (p. 249), which Dr. Whit- 
man Cross, of the United States Geological Survey, determines as 
vogesite. It has much augite and brown hornblende, biotite, and 
magnetite iq a feldspathic base, probably of orthoclase, also a few 
porphyritic crystals of olivine altered to serpentine. 

There is also a slightly altered diabase dike crossing the aplite of the 
Miller qyarry, in Hingliam (p. 279). 


At the Blanchard quarry, in Uxbridge (p. 283), the biotite granite 
gneiss is crossed by veins or dikes of medium smoky quartz banded 
lengthwise with feldspar (specimen D, XXX, 114, c). The feldspar 
bands are from 0.2 to 0.5 inch wide and the quartz from 0.5 to 1.5 
inches. The feldspar is microcline. The quartz contains many 
sheets of cavities parallel to bands and vein, also a few such sheets 
crossing the others at right angles. These sheets, where most abun- 
dant, are from 0.25 to 1 .33 millimeters apart. The longitudinal sheets 
of cavities are continued in outjutting parts of the adjacent feldspars 
as cracks. Such veins are to be regarded as a variety of pegmatite in 
which quartz and feldspar were deposited alternately." 

1 Should wliat was taken to be an elongated segregation in the biotite granite of the Redstone quarry, at 
Westerly, R. L (Bull. U. 8. Oeol. Survey No. 364, 1908, p. 202), prove to be a diorite schist dike, then some 
of the rdations there would duplicate those at New Bedford, for at the Redstone quarry the schist is also 
crossed by pegmatite and the i)egmatite by a diabase dike. 

> See Dale, T. N., Bull. V. S. Oeol. Survey No. 354, 1908, pp. 59, (SO. Qough, C. T., Crampton, C. B., and 
Fleet, J. S., The augen gneiss and Molne sediments of Roes^hire: Oeol. Mag., new ser., decade 5, vol. 7, 
London, August, 1910, p. 344. 

* See section on the relation of rilt and grain to sheets of cavities. Bull. U. S. Qeol. Survey No. 354, 1908, 
pp. 42-47. 

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The hornblende granite of High Rock, in Wrentham (Curry quany, 
p. 274), besides the usual sheet and joint structure, has steep headings 
at irregular intervals in its upper part. Tliese are only 5 to 10 feet 
deep and several feet wide, differing from ordinary headings in the 
closeness of their joints, which are only 1 to 2 inches apart. This 
structure is analogous to ''shake structure," which, however, is par- 
allel to tlie sheets. There are no joints in tliis quarry parallel to these 
minute headings, which are probably to be attributed to peculiar 
vibratory strains. 


New England olive-green granites from Rockport, Mass.,^ Red- 
stone,* and Kilkenny, N. H.,* and Mount Ascutney, in Windsor, Vt.,* 
have already been described. That of Rockport is a hornblende gran- 
ite, that of Redstone a biotite-homblende granite, that of Kilkenny an 
augite-biotite granite, and that of Windsor a homblende-augite gran- 
ite. The green granite of Peabody and Lynnfield (pp. 255-258) is also a 
homblende-augite granite, but contains less quartz and more dark 
silicates. It is analogous to the riebeckite-agirite granite of Quincy, 
but its black siUcates contain extremely little or no soda.* 

Washington • refers to this green granite in these words: 

The rocks belonging to this class were first noticed by Wadsworth in 1885 and were 
later described more in detail by Sears. Rosenbusch has expressed the opinion that 
these are related to the akerite type of syenites, a keen observation which my study 
of the rocks fully confirms. These rocks are found chiefly in the eastern part of Essex 
County, in Essex, Beverly, Manchester, Gloucester, and on Gape Ann. * « « The 
color even of the freshest specimens is greenish, which varies in shade from a dark 
greenish black to a light shade of greenish gray. 

In conmion with the green granites of Rockport and Redstone, that 
of Peabody and Lynnfield contains considerable allanite, to the oxida- 
tion of which the green color is partly dueJ 


Zones along which numerous microscopic parallel meandering 
fractures have been made and shearing has occurred, giving rise to 
secondary minerals and plicating the lamellad of plagioclase, were 
observed at one of the Fall River quarries. (See p. 250.) 

I BoU. U. S. Oeol. Sunrey No. 364, 1906, pp. 124, 135. 

> Idem, pp. 182, 183. 

B Bull. U. S. Geol. Survey No. 430, 1910, pp. 35ih-366. 

« Bull. U. S. Geol. Survey No. 404, 1909, pp. 116-119. 

ft Bull. U. S. Oeol. Survey No. 354, 1906, pp. 91-93. 

• Washington, H. S., The petrographical province of Eosex County, Maae.: Jour. Gedogy, vol. 6, 1898, p. 
787. See alao Sears, J. H., The physical geography, geology, mineralogy, and paleontology of Eaaex County, 
Mass., Salem, Mass., 1905, pp. 178, 190. 

7 Bull. U. S. Geol. Survey No. 354, 1906, p. 52, flg. 3. 

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Of special economic interest is the utilization of the exti-emely hard 
and almost sheetless aplite of Hingham, which is full of limonitic 
headings. (See p. 278.) For a number of years there has been a 
demand in the vicinity of Boston for rusty seam-faced granite for the 
exteriors of buildings, and quarries were opened in Hingham to supply 
such stone. It is now furthermore proposed to transform these ordi- 
nary obstacles to granite quarrying into things of beauty by carving 
bas-reUefs of leaves and garlands on the iron-stained joint faces. This 
is done by cutting away the sap or rusty part, which is usually from 
one-eighth to one-fourth inch thick, so that the leaves in brown pro- 
ject on a light-grayish ground. Blocks thus worked can be utilized 
in ornamental bands on exteriors. Sap-faced sheets are utilized as a 
by product at one of tlie Rockport quarries.* One of the Hingham 
quarries fills orders for sap-faced coigns with angles of 90® or 120°. 
The apUte, owing to its exceptionally great compressive strength, 
has also been found useful for keystones in tunnel arches. 

Although felsite porphyry is not a granite, it is a related igneous 
rock of important constructional value. The purplish-brown felsite 
porphyry of Black Ann Hill, in Revere (p. 279), has been found to be 
valuable for concrete construction, and a very large quantity of it 
was used in the East Boston tunnel. Tests made by the engineer 
of the Boston Transit Commission show that beams of 30-inch span, 
made with broken stone and the felsite dust from the crusher (pre- 
sumably with }-inch screenings), have an average breaking strength 
15.74 per cent higher than beams made with the same broken stone 
and sand. (See p. 280.) The superiority of felsite dust to sand for 
concrete is probably due to the fact that the angularity of the vitre- 
ous fragments is greater than that of water-rolled ouartz and feld- 
spar grains. 

A noticeable feature at many of the granite quarries is the recent 
addition of a stone crusher for turning the small waste into material 
for concrete, and even the ''dust" from the crushers is in demand. 
Most of the waste is now consumed in paving blocks and crushed 

Some general remarks on Massachusetts granites are given on 
page 288. 


The granite and quarry descriptions are arranged alphabetically 
by counties and townships. 

t See Bull. U. 8. Geol. Survey No. 354, 1908, pp. 69, 125, and for the cause of the stain pp. 56-68. 

Digitized by 





The Dartmouth quarry is in Dartmouth Township, three-fourths 
of a mile east of Westport Mills and 8t miles southeast of the Fall 
River steamboat wharf. (See map of Fall River quadrangle, U. S. 
Geol. Survey, and PL V.) Operator: New Bedford & Dartmouth 
Granite Co., 81 Austen Street, New Bedford, Mass. 

The granite (specimen D. XXX, 122, a), ''Dartmouth," is a 
gneissoid biotite-muscovite granite of very light buff-gray color and 
of very slightly gneissoid, medium inclining to coarse texture with 
feldspars up to 0.5 inch and mica up to 0.1 inch. Its constituents, 
in descending order of abundance, are cream-colored, translucent 
microperthite (potash feldspar (microcline), minutely intergrown with 
lime-soda feldspar (oUgoclase-albite) and somewhat kaolinized) ; pale, 
smoky quartz, with cavities, in sheets; clear to translucent soda-Ume 
feldspar (oligoclase-albite); but Uttle kaolinized; and muscovite 
(white mica) and biotite (black mica) in about equal amounts. 
Accessory: Garnet. Secondary: Kaolin and carbonate. It shows 
extremely Uttle effervescence with hydrochloric-acid test. This is a 
serviceable constructional stone with feeble mineral contrasts. 

The quarry, opened in 1903, is about 150 by 100 feet and 30 feet 
deep, with a working face 45 feet high on the west. The stripping 
consists of 6 feet of sand. 

The sheets, from 1 to 12 feet thick, are about horizontal. The 
joints, all discontinuous, are of three sets: Set a strikes N. 75° E., 
dips 75° S. 15° E.; on the north and -south walls only. Set 6 strikes 
north, dips 50° E., is spaced 3 to 10 feet; forms the west wall. Set c 
strikes N. 25° W., dips 65° N. 65° E. ; one only. The rift is horizontal 
and the grain vertical with N. 60° E. course. There are small peg- 
matite and smoky quartz dikes with N. 60° W. courses. Rusty 
stain is up to 3 inches thick on sheet surfaces, diminishing at the 
bottom of quarry. 

The plant comprises three derricks, two hoisting engines, two steam 
drills, an air compressor (capacity, 100 cubic feet of air per minute), 
seven air-plug drills, and two steam pumps. 

Transportation is by cart to New Bedford, 5i miles. 

The product is used for local buildings, curbing, and paving. 
Specimen: Trimmings on Limds Comer schoolhouse. New Bedford. 


The Alfred Denault quarry is in Dartmouth Township, just west 
of the Dartmouth quarry, and its granite is identical. 

This is a small opening begun in 1910. The stripping is not over 
18 inches of sand. In June the first sheet had been exposed to a 
depth of 5 feet. 

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The plant comprised a hand derrick and hoisting engine, and the 
product is curbing. 


The Beattie & Wilcox quarry is in the city of Fall River, near 
Watuppa Pond and the railroad, 2^ miles southeast of the steamboat 
wharf. (See map of Fall River quadrangle, U. S. Geol. Survey.) 
Operators: Beattie & Wilcox, 840 Bedford Street, Fall River, Mass. 

The granite is of two colors. One (specimen D, XXX, 116, a), 
'^Fall River pink," is a gneissoid biotite granite of medium pinkish- 
gray color, with black spots, and of gneissoid, coarse, inclining to 
medium texture, with feldspars up to 0.5 inch and mica up to 0.4 inch. 
Its constituents, in descending order of abundance, are pinkish micro- 
perthite (potash feldspar (orthoclase and microcline), minutely inter- 
grown with sodarlime feldspar) ; milky quartz, granulated (particles 
mostly under 0.5 miUimeter), with some cavities in sheets; milk- 
white soda-Ume feldspar (oligoclase-albite), a little micasized and 
epidotized; biotite (black mica), mostly chloritized; and a little 
bleached biotite or muscovite. Accessory: Garnet and titanite. 
Secondary: Epidote, usually about the biotite, a white mica, chlorite, 
very little carbonate, and hematite stain. Some of the second feld- 
spar has bent lamellaB. It shows no eflFervescence with hydrochloric- 
acid test. 

The rock of the other color (specimen D, XXX, 116, b), ''Fall 
River gray," is a gneissoid biotite granite of light buff-gray color with 
inconspicuous black spots and of gneissoid, medium inclining to 
coarse texture, with feldspars up to 0.4 inch and mica up to 0.3 inch. 
Its constituents are the same as in the ''pink," except that the 
microperthite is pale buff to pinkish, the second feldspar is light 
greenish, and the granulated quartz is clear and colorless, its particles 
measuring up to 0.75 millimeter. Among the secondary minerals is 
a little limonite stain. No carbonate detected nor effervescence. 

These granites have in places flowage bands in which one band con- 
tains many more than the average of biotite spots, and the next 
contains many less and is also finer grained than the general mass, 
resembling an apUte. 

These are very suitable granites for massive structures. The pink 
has more mineral contrasts than the other. 

The quarry, opened in 1893, is about 400 by 200 feet and 10 to 40 
feet deep. 

The sheets, from 18 inches to 16 feet thick, undulate horizontally. 
Joint courses, etc., are shown in figure 40. Set a dips steeply N. 70° 
W., is spaced 50 feet, forms the west-southwest wall and a heading 
20 feet wide 50 feet east of it. Set fc, vertical, is spaced 20 to 200 feet. 

Digitized by 



The flowage bands described dip steeply S. 30^ W. Shear zones dip 
65^ NW.y measure up to an inch in width, and are spaced 2 to 3 feet. 
The extremely fine, roughly parallel meandering planes of dark 
schistose material within the zones are fractures filled in their wider 
parts with epidote, carbonate, and muscovite. Veinlets of quartz 
cross the feldspars, about which there is some granulation. The 
lamellsB of the soda-lime feldspars are much bent, and some are even 
minutely plicated. The rift is horizontal, and the grain dips about 
like the joints of set a. A black, extremely fine grained basaltic dike, 
described on page 245, is 6 inches to 4 feet thick and weathers sphe- 
roidaJly. The ''sap" is 1 to 8 inches thick on sheet surfaces. 

The plant comprises three derricks, two hoisting engines, two steam 
drills, a steam pmnp, and a stone crusher of 75 tons daily capacity. 

The product meets local demands mostly. Specimens: Armory, 
city library, Flint mills. Fall River; Banigan Chapel, in cemetery of 

Pawtucket; ''Stone bridge" to Rhode 
Island and naval training station, 
Newport, R. I. 


The Beattie quarry is in Fall River, 
1 i miles west of the steamboat wharf. 
Operator: William H. Beattie, 33 
North Quarry street. Fall River, 

The granite is of two colors. One 
(specimen D, XXX, 117, a), "Fall 
River pink," is a gneissoid biotite 
granite of light pintdsh-^ray color 
with black spots and of slightly gneissoid, coarse texture, with 
feldspars and mica up to 0.5 inch, the mica exceptionally reaching 0.6 
inch. Its constituents, in descending order of abundance, are pinkish 
microperthite (potash feldspar (microcline and orthoclase),someof it 
epidotized, minutely intergrown with soda-lime feldspar) ; clear, color- 
less quartz, granulated, with particles mostly imder 0.5 inch, and with 
cavities, some in sheets, and rutiie needles; and greenish to milk- 
white soda-lime feldspar (oligoclase-albite), micasized and epidotized, 
some of its particles with bent lamelleB. Accessory: Allanite, zircon, 
rutiie. Secondary: Fibrous muscovite stringers, another white mica, 
epidote, carbonate. It effervesces with hydrochloric-acid test. 

The rock of the other color (specimen D, XXX, 117, b), "Fall River 
gray,'' is a gneissoid biotite granite of light-gray shade with conspicu- 
ous black and greenish spots and of slightly gneissoid, coarse inclining 
to medium texture. Its constituents, in descending order of abun- 
dance, are translucent grayish microperthite (potash feldspar (ortho- 
clase and microcline), minutely intergrown with soda-lime feldspar); 

FiGUBE 40.--Stnicture at Beattie & Wilooz 
quany. Fall River, Mass. 


zed by Google 


faintly purplish milky quartz, granulated, with particles under 0.5 
inch and with cavities; gray to pale greenish, not translucent soda- 
lime feldspar (oligoclase-albite), micasized and epidotized; biotite 
Cblack mica), some chloritized, generally with epidote; and a little 
bleached biotite or muscovite. Accessory: Allanite, garnet, and 
magnetite (very little). Secondary: Carbonate, a white mica, 
epidote, chlorite, and hematite stain. 

Jhese granites are very similar to those of the Beattie & Wilcox 
quarry, but they differ in that the pink is of lighter shade, and the gray 
has more marked mineral contrasts. Both pink and gray are attrac- 
tive stones, well adapted for massive structures. 

The quarry, opened before 1866, is 900 by 700 feet and from 20 to 60 
feet deep. The strippiag consists of 2 to 6 feet of gravel and bowlders. 

The sheets, from 8 inches to 8 feet thick, are horizontal or dip 5° to 
10® SE. Joint and dike coiu'ses are 
shown in figure 41. Joint set a forms a 
heading 30 feet wide through the center 
of the quarry and is spaced 20 to 125 
feet, with slickensided sericite-<;oated 
close joints parallel to it (specimen D, 
XXX, 117, c). Set 6, vertical, forms 
the south wall and is spaced about 40 
feet. Set c, vertical, forms a heading 
50 feet wide diagonally through the 
quarry. The rift is horizontal and the 
grain scarcely perceptible. A 3-inch 
pegmatite dike containing much quartz ^®^"*^ "^^^^"m^"** '*'""^' 
dips 43® N. '65® W. and has shear zones 

along it with small micaceous or chloritic masses. An aplite dike 
is 4 inches thick. Dark segregations measure up to 3 inches across. 
Ldmonite stain is up to 6 iaches thick on sheet surfaces. 

The plant comprises five derricks, three hoisting engines, an air 
compressor (capacity 550 cubic feet of air a minute), fourteen air 
plug drills, two surfacers, three steam drills, and a stone crusher with 
2i, li, and | inch meshes, and a daily capacity of 80 tons. 

Transportation is by cart to railroad or wharf 1^ miles. 

The product is used mostly for buildings. and wharves. The waste 
goes iuto curbing, paving, and crushed stone. Specimens: Saga- 
more Manufacturing Co.'s mill, wharves of Fall River Iron Works, 
Bristol County jail. Fall River; Bristol Coimty courthouse (except 
trimmings, which are of Woodbury (Vt.) granite, Taunton; Naval 
War College building, Newport, R. I. 

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The Sa7oie quarry is on Beauregard Street, in Fall River, If miles 
east-southeast of the steamboat wharf. Operator: H. Savoie, 85 
Beauregard Street, Fall River, Mass. 

The granite is a gneissoid biotite granite of light-gray shade with 
conspicuous black and greenish spots and of coarse inclining to me> 
dium texture, closely resembling the *'gray" of the Beattie quarry 
described on page 250. < 

The quarry, opened in 1895, is 200 by 100 feet and 30 to 40 feet 
deep. The stripping consists of 5 to 13 feet of sand and bowlders. 

TOie sheets, 2 to 6 feet thick, are horizontal. There are four sets 
of joints. Set a, vertical, strikes N. 60° W.; forms a heading on the 
north waU. Set 6, steep to vertical, strikes N. 10^-20° W. ; forms the 
east and west walls and a heading 20 feet wide at the south end and 
is spaced 5 to 60 feet. Set c strikes NE., dips 30° NW. ; only two, 12 
feet apart. Set d, diagonal, strikes N. 20° E., dips 66° S. 70° E.; is 
spaced 5 to 40 feet. The rift is horizontal and grain vertical with 
north-south course. A dark brownish-gray apUte dike, 6 inches to 2 
feet thick (specimen D, XXX, 118, b), strikes east-west. There is also 
a pinkish apUte dike 10 feet wide (specimen 118, a). Both these 
aplites are described on page 242. Quartz veins and shear zones strike 
N. 60° E., and dip 50° N. 30° W. There is no ''sap" away from 

The plant comprises three derricks, a hoisting engine, an air com- 
pressor (capacity 200 cubic feet of air a minute), four air plug drills, 
a steam drill, and two steam pumps. 

Transportation is by cart to dock or rail, 2\ miles. 

The product is used for buildings, curbing, and paving and its 
market is mostly local. Specimens: City library. Maple Street 
School (trimmings), Fall River. 


The Sears quarry is in Fall River, about \\ miles east of the steam- 
boat wharf. Operator: C. H. Sears, Fall River, Mass. 

The granite is a gneissoid biotite granite of light-gray shade with 
conspicuous black and greenish spots and of coarse inclining to 
medium texture, like the "gray" of the Beattie quarry described on 
page 250. 

The quarry, opened in 1892, is 125 by 75 feet and 20 feet deep. 
The stripping consists of 5 to 10 feet of clay and sand. 

The sheets, 1 to 8 feet thick, undulate. There are two sets of joints. 
Set a, not far from east-west, forms the north wall and a heading 15 
feet wide through the center of the quarry and is spaced 2 to 20 feet. 
Set ft, nearly north-eouth, forms the west wall and is spaced 10 to 20 
feet but in places crosses one sheet only. The rift is horizontal and 

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the grainy vertical, north-€(outh, but scarcely perceptible. There is 
little ''sap'' away from headings. 

The plant comprises a derrick, a hoisting engine, a small air com- 
pressor, two air plug drills, a steam drill, and a steam pump. 

Transportation is by cart. 

The product is used for local buildings. Specimen: Lower story 
of Textile School, Fall River. 


The Ross quarry is at the head of Barlow Street, near Watuppa 
Pond, in Fall River, 2i miles about southeast of the steamboat wharf. 
(See map of Fall River quadrangle, U. S. Geol. Survey.) Operator: 
George Ross, 69 Pitman Street, Fall River, Mass. . 

The granite (specimen D, XXX, 119, a), ''Fall River, Barlow 
Street," is a gneissoid biotite granite of medium bluish-gray color and 
of medium texture, with feldspars up to 0.3 inch and mica up to 0.1 
inch. Its constituents, in descending order of abundance, are 
pinkish cloudy microperthite (potash feldspar (orthoclase and micro- 
cUne) , minutely intergrown with soda feldspar) ; clear colorless quartz, 
granulated, with particles nearly all under 0.5 millimeter; clear 
colorless to pale-greenish soda feldspar (albite), micasized and 
epidotized; and biotite (black mica), some of it chloritized, associated 
with epidote and a little muscovite or bleached biotite. Accessory: 
Garnet. Secondary: Muscovite in stringers, also a white mica in 
the albite, epidote, carbonate, and chlorite. It shows no effervescence 
with hydrochloric-acid test. 

As will be noticed from the description, this stone differs from the 
other Fall River gray granites in the absence of the large black micas. 
The second feldspar here is pure albite. The mineral contrasts are 

The quarry, opened before 1901, is 125 feet square and 30 feet deep. 
The stripping consists of 5 to 10 feet of sand and bowlders. 

The sheets, 1 to 5 feet thick^ on the east side, are lacking on the 
west side. There is only one joint, striking east-west and forming 
the south wall. The upper sheets are badly discolored. 

The plant comprises three derricks, a hoisting engine, a small air 
compressor, two air plug drills, a steam drill, and a steam pump. 

Transportation is by cart. 

The product is curbing, crossing flags, and paving stones for local 


The Sullivan quarries are near Rockdale hi the township of New 
Bedford, 2 miles northwest of the city. (See map of New Bedford 
quadrangle, U. S. Qeol. Survey, and PL V.) Operators: John B. 
Sullivan & Son, New Bedford, Mass. 

Digitized by 



The granite (specimens D, XXX, 121, a, pinkish, and b, less 
pinkish), *'New Bedford," is a biotite-muscovite granite gneiss of 
light pinkish-graj color and of slightly gneissoid, coarse inclining to 
medium texture, with feldspars up to 0.5 inch and mica up to 0.1 
inch. Its constituents, in descending order of abundance, are light- 
pinkish potash feldspar (microcline), soma of it slightly kaolinized; 
medium smoky quartz with cavities and black particles in parallel 
sheets; milky soda-lime feldspar (oligoclase-albite) ; biotite (black 
mica), some of it chloritized; and muscovite (white mica). Acces- 
sory: Garnet, magnetite, fluorite, apatite, and zircon. Secondary: 
Kaolin, epidote, chlorite, and limonite.. No carbonate or pyrite 
detected. It shows no effervescence with hydrochloric-acid test. 

This is an attractive and substantial building stone. Its mineral 
contrasts are a little more marked than those of the Dartmouth 
granite. The absence or scarcity of pyrite and carbonate are in its 

The quarries comprise two openings. The main one, begun about 
1860, is 600 by 150 feet and from' 60 to 75 feet deep. The other, 
about 300 feet farther south, formerly known as the Denault quarry, 
is about 250 by 150 feet and from 50 to 70 feet deep. Dike, joint, 
and grain courses are shown in figure 39 (p. 244). The sheets in the 
main quarry are from 10 to 25 feet thick, but for a space of 5 or 6 
feet on either side of the dikes there are sheets from 3 to 18 inches 
thick, which were evidently formed after the dikes and largely in con- 
sequence of them. There are two sets of joints. Set a, coated with 
epidote, is vertical and spaced 50 feet. Set 6, confined to the Denault 
quarry, dips 55** E., is spaced 2 to 30 feet, with a heading at east 
wall and another 10 to 18 feet wide near it. The rift is horizontal. 
The dikes have been described on page 244. There is one each on the 
north, south, and west walls, through the center, and another of peg- 
matite near the west wall. The amount of rusty stain is small. 

The plant comprises seven derricks, five hoisting engines, three air 
compressors (capacity 270 cubic feet of air a minute), twenty air plug 
drills, two surfacers, six steam drills, three steam pumps, and a stone 
crusher with adjustable screens and a daily capacity of 100 to 115 

Transportation is by cart to New Bedford, 2 or 3 miles. 

The product is used for local buildings and streets. Specimens: 
Armory, public Ubrary (90 per cent, the rest being from Fall River 
quarries), St. James and St. John Roman Catholic churches, and 
trimmings to most of the cotton mills, New Bedford, 

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The Robin Rock quarry is in Lynnfield Township, four-fifths of a 
mile south-southeast of South Lynnfield station. (See map of Law- 
rence quadrangle, U. S. Geol. Survey.) Operator, Arthur L. Kal- 
lenberg, Lynnfield, Mass. 

The granite (specimen D, XXX, 127, a), ** Robin Rock green," is 
a homblende-augite granite of ve ry dark greenish-gray color andof 
coarse even-grained texture, with feldspars up to 0.6 inch and black 
silicates up to 0.4 inch. Its constituents, in descending order of 
abundance, are dark-blue or greenish-gray microperthite (potash 
feldspar (orthoclase), minutely intergrown with soda feldspar (albite) 
and kaolinized) ; very dark, slightly greenish smoky quartz, with cavi- 
ties in sheets intersecting at right angles; black (under the microscope 
greenish) hornblende with inclusions of allanite; very little separate 
soda feldspar (albite); and black (under the microscope greenish) 
augite. Accessory: Magnetite, allanite, pyrite, zircon, and a Uttle 
biotite. Secondary: Kaolin and limonite stain. It shows no effer- 
vescence with hydrochloric-acid test. 

Another variety (specimen D, XXX, 127, b), '^ Robin Rock gray," 
is also a homblende-augite granite but of dark-gray shade, speckled 
with black, and of coarse even-grained texture, with feldspars up to 
0.7 inch and black siUcates up to 0.3 inch. Its constituents appear to 
be the same as the other variety, but, as shown by effervescence with 
acid test, carbonate is present. The microperthite is dark gray in 
the hand specimen but shows some limonite-stained faces. Augite 
is intergrown with hornblende or passing into it. Apatite appears 
among the accessory minerals and zircon is rather plentiful. This 
stone probably becomes somewhat greenish on continued exposure. 

This stone appears well when fine pointed. The scientific interest 
of green granites has been noted on page 246. 

There are several openings, some of which are a century old. The 
one now worked is triangular in area, 75 feet on a side and 5 to 25 
feet deep. The stripping is 1 or 2 feet of loam. 

The sheets, from 18 inches to 6 feet thick, dip 10^ E. There is only 
one set of joints, vertical, with N. 80° W. strike, spaced 3 to 12 feet, 
with a heading 15 feet wide on the north side. The rift is vertical, 
with east-west course, and the grain vertical, north-south. ''Knots" 
measure up to 6 inches. The stain on sheet surfaces is yellowish for 
an inch, then for 2 inches the stone is pale. 

The plant comprises five hand derricks. 

Transportation is by cart to Wakefield and Reading, 4 to 6 miles. 

The product is used for buildings, foundations, sills, steps, and 

Digitized by 




The Linehan quarry is in Peabody Township, on a knoll one-fourth 
of a mile east of Bartliolomew Pond, about 3 miles west-southwest of 
Peabody. (See map of Salem quadrangle, U. S. Geol. Survey, and 
PL V.) Operator: James C. Linehan, 18 Foster Street, Peabody, 

The granite (specimen D, XXX, 128, a), "Peabody green," is a 
hornblende-augite granite of very dark olive greenish-gray color and 
of even-grained coarse testure, with feldspars up to 0.7 inch and black 
silicates up to 0.2 inch. Its constituents, in descending order of 
abundance, are dark olive greenish-gray microperthite (potash feld- 
spar (orthoclase), minutely intergrown with plagioclase, probably 
soda feldspar, kaolinized and with crush borders) ; very dark green- 
ish smoky quartz, with cavities in sheets intersecting, some at right 
angles, and with cracks filled with limonite stain; green hornblende; 
and augite intergrown with or passing into the hornblende. Acces- 
sory: Magnetite, allanite, rather plentiful zircon, and apatite needles. 
Secondary: Kaolin, limonite stain, and carbonate. It shows slight 
effervescence with hydrochloric-acid test. 

This granite differs from the green of the Robin Rock quarry 
(p. 255) only in its more yellowish tinge. When first quarried it is 
grayish, but within a week it becomes yellowish green. (See p. 246.) 

The quarry, opened in 1900, is 260 feet east and west by 80 and 
100 feet across and 20 to 40 feet deep. 

The sheets, from 8 to 16 feet thick, are lenticular and horizontal. 
There are three sets of joints. Set a, vertical, strikes N. 15^ E.; on 
east and west walls only, 250 feet apart. Set &,''rift joints" diagonal 
strikes N. 70° E., dips 65° S. 20° E., is coated black with hornblende,* 
also with calcite up to 0.12 inch thick, and is spaced 30 to 60 feet. 
The rift, which is marked, is parallel to set J, the grain is at right 
angles to it, and the hardway horizontal. Dark-gray knots are from 
half an inch to 12 inches across. The stain forms a dark-brown sur- 
face on the sheets with an mch of pale granite below it; in places, 
however; the brown part is an inch thick and the pale granite 2 inches. 
The joints are also discolored in this way. 

The plant comprises three hand derricks, a hoisting en^e, a steam 
drill, and a steam pump. 

Transportation is by cart, an average of 3 miles. 

The product is used for street work and trimmings. Speoimen: 
Trimmings on addition to Mercantile Bank, Salem, Mass. 

1 These black-coated Joints are analogous to those of the Quincy quarries, where, however, the mhieral is 
the soda hornblende, riebeckite. Th«3r signify xnetamorphism after the Jointing. See Buil. U. 6. OeoL 
Survey No. 354, 1906, pp. 60, 61. 

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The Caron quarry is in Peabody Township, about one-fourth mile 
south-southeast of the town farm on Lynnfield Street. (See map of 
Salem quadrangle, U. S. Geol. Survey.) Operator: M. Caron, Per^ 
kin Street, Salem, Mass. 

The granite, "Peabody green,'' is a homblende-augite granite of 
very dark olive greenish gray color and of even-grained coarse texture 
like that of the linehan quarry, described on page 256. 

The quarry, opened in 1898, is 75 by 30 feet and from 10 to 30 feet 
deep. The stripping is up to 6 inches thick. 

This is a "bowlder quarry" yielding blocks 18 feet thick. There 
are two sets of joints. Set a strikes N. 77® E., dips eo"" S. 13° E., 
is spaced 10 to 20 feet. Set 6 strikes N. 40° E., dips 50° N. 50° W. 
and is spaced over 30 feet. The rift is parallel to set a and the grain 
dips 70° about west. The "sap" is up to 3 inches thick on masses 
below the surface, half of it being brown. 

The plant comprises a hand derrick and a steam drill. 

Transportation is by cart to Lynn, Salem, Beverly, and other places. 

The product is used for trimmings and curbing. Specimens: 
Trimmings on hotel at comer of Mill and Washington streets, and on 
store at comer of Derby and Dinell streets, Salem. 


The Den quarry is on the Peabody and Lynn town line, about 2f 
miles north-northwest of Lynn station. (See map of Boston Bay 
quadrangle, U. S. Geol. Survey.) Operator: C. E. Mudge, Lynnfield 
Street, Lynn, Mass. 

The granite (specimens D, XXX, 126, a, b), "Peabody green," is 
a homblende-augite granite of dark to very dark olive greenish gray 
color. When first quarried the feldspars are less greenish and lighter 
and the general color corresponds, but this soon changes. Its texture 
is even grained coarse, with feldspars up to 0.7 inch and black silicates 
up to 0.4 inch. Its constituent, in descending order of abundance, 
are medium but soon becoming dark greenish-gray microperthite 
(potash feldspar (orthoclase), minutely intergrown with soda feldspar 
(albite), much kaohnized, with cmsh borders and with cracks filled 
with Umonite stain) ; very dark yeUow-greenish smoky quartz, with 
cavities in sheets, some intersecting at right angles, and with cracks 
parallel to them filled with hmonite stain; black hornblende (green 
in section), with inclusions of allanite; and black augite (green in 
section), intergrown with or passing into the hornblende, also with 
inclusions of allanite. Accessory: Magnetite, allanite, zircon, apa- 
tite, and very little biotite. Secondary: Limonite stain proceeding 
from the allanite and augite and following the boundaries of particles 
and cracks, kaolin, a brown and also a blue hornblende (probably 

94174'— Bull. 470—11 1T 

Digitized by 



nebeckite) in fibrous crystals growing out of the augite surfaces into 
quartz and feldspars, and carbonate. It shows very slight effer- 
vescence with hydrochloric-acid test. 

This stone is reported to take a good polish, which might be 
expected from its lack of mica. (See, for discussion of green gran- 
ites, p. 246.) 

The quarry, opened about 1905, is about 100 feet square and 20 to 
60 feet deep. 

The sheets, 16 to over 30 feet thick, dip 20'' S. 55° E. There are 
four sets of joints. Set a, discontinuous, strikes N. 5° E., dips 75° E., 
forms a heading on east wall, is spaced 30 to 40 feet. Set I, vertical, 
strikes east-west; forms a heading 100 feet wide on east wall, is 
spaced 25 to 40 feet. Set c strikes N. 40° W., dips 47° S. 50° W.; 
one only. Set d, vertical, strikes N. 30° W.; one only. The rift 
dips steeply S. 60° W. and the grain, which is almost as pronounced 
as the rift, is horizontal. Very dark gray s^regations (knots) are 
up to 0.5 inch, exceptionally 2 feet, across. A thin section of one 
of these knots (specimen D, XXX, 126, d) shows a groundmass of par- 
ticles of microperthite and plagioclase (probably albite) from 0.1 to 
0.3 millimeter in diameter, with thickly disseminated particles of 
augite from 0.02 to 0.37 millimeter, and minute grains of magnetite. 
At the edge is a large porphyritic microperthite, a crystal of zircon, 
and a particle of augite associated with a blue hornblende, biotite, 
magnetite, and zircon. 

The feldspars on the sheet surfaces are generally much kaolinized. 
The rusty stain (specimen D, XXX, 126, c) measures up to an inch 
in thickness and the pale-green band below it from 2 to 4 inches. A 
top sheet, 12 feet thick and 100 by 40 feet in area, is all discolored. 

The plant comprises two hand derricks. 

Transportation is by cart, mostly to Lynn, nearly 3 mUes. 

The product is used for base courses, steps, curbing, crossings, caps, 
and paving. The rusty faces are used for base courses. Specimens: 
Starr Parsons monument in Pine Grove Cemetery, and sap-faced base 
course of dwelling at comer of Wave and Ocean streets, Lynn. 


Several other quarries of this granite west and southwest of Pea- 
body in that township, which were not operated in 1910, were not 




The Flynt quarries are in Monson Township on the southwest side 
of Bunyan Mountain, IJ miles north-northwest of Monson station. 
(See map of Palmer quadrangle, U. S. Geol. Survey, and PI. V.) 
Operator: William N. Flynt Granite Co., Monson, Mass. 

Digitized by 



The granite (specimens D, XXX; 90, a, b; c), ''Monson'' (darker 
variety, used for faces of buildings); is a biotite-quartz monzonite 
gneiss of dark to veiy dark gray shade and fine to very fine elongated 
(unplicated) gneissic texture, with feldspars and mica up to 0.2 inch, 
but mostly under 0.1 inch. Its constituents, in descending order of 
abundance, are clear colorless quartz with cavities; bluish trans- 
lucent potash feldspar (microcline and orthoclase); milk-white soda- 
lime feldspar (andesine); and biotite (black mica). Accessory: Mag- 
netite (fifth in order of abundance), garnet, zircon, apatite, and 
allanite. Secondary: Epidote (sixth in order of abundance) and chlo- 
rite. It shows no effervescence with hydrochloric-acid test. No 
pyrite is visible on the polished face. 

A light to medium gray variety (specimen 90, c) with fine bands 
of dark gray has the same composition as the rock described above, 
but less biotite. This stock is used for curbing, foundations, etc. 
- The Monson gneiss is now regarded by B. K. Emerson as of igneous 
origin and probably of Carboniferous age. 

The following analysis of it was made by W. F. Hillebrand: * 

Analysis of Imtite-quartz moTuonite gneiss from Flynt quarry ^ Monson^ Mass, 

Silica (SiOJ 65.02 

Alumina (AI2O,) 18.37 

Iron seequioxide (FcjO,) 1. 21 

Iron oxide (FeO) 2.06 

Magnesia (MgO) 1.49 

Lime(OaO) 6.20 

Soda(Na20) 3.96 

Potash (KaO) 64 

Water (H3O at 106°) 09 

Combined water (H3O above 105**) 42 

Titanium dioxide (TiOa^ 33 

Carbon dioxide (OOj) None. 

Phosphoric acid (PjOj) 14 

Manganese oxide (MnO) 09 

Barium oxide (BaO) Trace. 


Merrill * states that a test of this gneiss showed a crushing strength 
of 15,390 pounds per square inch with the pressure appUed at right 
angles to the foliation, and 12,720 pounds with the pressure applied 
in the direction of the foliation. 

The fine and even foUation of this gneiss renders it more suitable 
for some purposes and less for others than a true granite. The 
absence of pyrite in its composition is much in its favor as a building 
stone. Its foliation prevents its taking a high polish. 

I BuU. U. S. aed. Survey No. 419, 1910, p. 22, Analysis I. 

• Merrill, Q. P., Stones for building and decoration, New York, ISOl, p. 406. 

Digitized by 



The first opening was made in 1824 by United States agents for the 
construction of the armory at Springfidd, Mass. The quarry now in 
operation is about 350 by 150 feet and from 20 to 30 feet deep. The 
stripping consists of 2 feet of sand. 

The sheets, 6 inches to 10 feet thick, but mostly 2 to 5 feet, dip 
6*^ to 20° W. The only joints are parallel to the foliation and are 
spaced 10, 50, and 90 feet. The gneiss foliation strikes N. 10° E. 
and dips 75° N. 80° W. The rock is of light, medium, and dark gray 
shades in alternating bands of very different widths. Some are not 
over 0.25 inch wide; others 2 or 3 feet. These bands are free from 
plications, but one was found doubled over on itself vertically for the 
space of a foot. Each band as seen on the sheet surface also varies 
greatly in width. Some foliation faces are chloritic. The rift cor- 
responds to the foliation and the grain is horizontal. A few pegmatite 
bands up to 3 inches thick occur. There is no rusty stain. 

The Monson quarries have long been referred to as affording evi- 
dence of compressive strain,^ but although the rock is still under a 
north-south strain, fracturing attended with explosive sounds no 
longer occurs.* 

The plant comprises eight derricks, five hoisting engines, a loco- 
motive, an air compressor (capacity 550 cubic feet of air a minute), 
forty air plug driUs, forty air hand tools, five surf acers, a polisher, a 
steam pump, and a stone crusher with screens of 2^, 1^, and } inch 

Transportation is by a l^-mile siding from the Central Vermont 
Railway at Monson. 

The product is used for buildings, bridges, and monuments; the 
seconds for curbing, foundations, and crushed stone for concrete. 
Specimens: Horatio Lyon Library, Monson; Walker Hall, Amherst 
College; Church of St. Francis Xavier on Sixteenth Street, and Isabella 
Home on One hundred and nineteenth Street, New York; Munn Mon- 
ument, Woodlawn Cemetery, New York; Roman Catholic Church and 
rectory, West New Rochelle, N. Y.; residence of Charles La Dow, 
Thurlow Terrace, Albany, N. Y.; Congregational Chiuxjh and Doane 
buildings, RockvUle, Conn.; fountain at Weatogue, Conn.; HaU 
Memorial Chapel, Watertown, Conn. ; high school, East Orange, N. J. ; 
Park Avenue Methodist Church, Chicago. 

& See Niles, W. H., Some interesting phenomena obeerved In quarrying: Proo. Boston 8oc. Nat. Hist, 
▼oL 14, 1872, pp. 80-87; vol. 16, 1874, pp. 41-43; also Emerson, B. K., Geology of Old Hampshire County, 
Mass.; Mod. U. 8. God. Survey, vol. 29, 1808, pp. 64, 65. 

• See, on this subject In general, Bull. U. 8. Geol. Survey No. 354, 1908, p. 28; BuU. 404, 1000, p. 17; also, 
on similar phenomena In the granite quarries of Quenast in Belgium; Hanlcar-Urban, A., Note sur des 
DumvamentsfpoataiifedesroohesdanslescanidreB: BulL 8oc. Beige gteL, pal., ethydrol., vol. lO^^nissels, 
1906, pp. 527-440, and other papera by same author in vol. 21, 1907, and vol. 23, 1900. 

Digitized by 



The Ward quarry is in Pelham Township, 2 miles northeast of 
West Pelham and about 4 miles east-northeast of Amherst. (See 
map of Belchertown quadrangle, U. S. Geol. Survey, and PL V.) 
Operator: E. P. Bartlett, R. F. D., West Pelham, Mass. 

The granite (specimens D, XXX, 91, a, b, c), 'Telham gneiss,'* 
is a biotite granite gneiss of very fine elongated (unplicated) gneissic 
texture and of general dark bluish-gray shade, with feldspars and 
mica under 0.1 inch. It is finely banded, the bands being mostly 
not over 0.04 inch wide and of very dark gray alternating with 
white. There are fine-grained white bands without black mica 
(specimen c). There are also lenses of quartz and feldspar up to 
0.3 inch wide and several inches long, containing black mica crystals 
up to 0.3 inch in diameter, lying transverse to the foliation (speci- 
men b). Its constituents, in descending order of abundance, are 
clear to translucent bluish potash feldspar (microcline and ortho- 
clase); very pale smoky quartz; biotite (black mica) with a httle 
muscovite; and very little milk-white plagioclase feldspar, kaolin- 
ized. Accessoiy: Magnetite, titanite, zircon, allanite, and apatite. 
Secondary: Kaolin, epidote, carbonate, and chlorite. It shows no 
effervescence with hydrochloric-acid test. 

An analysis of this gneiss made by George Steiger, a chemist of 
this Survey, follows: 

Analygis of hioHte granite gneiss from PeUumiy Mass} 

Silica (SiOa) 72.46 

Alumina (A1,0,) 13.32 

Iron sesquioxide (FejO,) 1. 93 

Iron oxide (FeO) 63 

Magnesia (MgO) 44 

lime(CaO) 1.81 

Soda(NaaO) 3.65 

Potash (KjO) 3.86 

Water (HjO at 106*») 69 

Combined water (HjO above 106**) 1. 51 

Titanium dioxide (TiOa) 27 

Phosphoric acid (PjOj) 06 


In comparing this analysis with that of the Monson gneiss (p. 259), 
it will be noticed that this has higher percentages of sQica and potash 
and lower of alumina, iron oxides, magnesia, and lime. The microscopic 
descriptions of the two rocks show that the Monson gneiss contains 
much more soda-lime feldspar than the Pelham stone. 

1 BoU. U. S. Geol. Survey No. 419, 1910, p. 22, analyiiB L. 

Digitized by VjOOQIC 


B. K. Emerson now regards the Pelham gneiss as of igneous 
origin and probably of Carboniferous age. 

The Pelham gneiss in appearance resembles that of Monson and 
its economic uses and value are similar. The shade of the Pelham 
stone is a trifle lighter than the best dark of the Monson quany. 

The quarry, opened before 1862 and now worked irregularly, 
measures about 200 feet in a northwest direction and has a working 
face 25 feet high on the northeast. The stripping consists of 6 to 10 
feet of sand. 

The sheets, from 6 inches to 2 feet thick, are parallel to the gneiss 
foliation, which strikes N. 80° W. and dips in undulations 5® to 13® N. 
10° E. The sheet surfaces are slickensided, with stri» striking N. 
10° E. There are no joints. The rift is parallel to the foUation 
and the grain probably vertical, with N. 10° E. course. Pegmatite 
dikes of light feldspar, smoky quartz, and biotite measure up to 
an inch thick, dipping 60° to 60° about north. Lenses of smoky 
quartz measuring up to 30 feet long and to 6 inches thick Ue in the 
foUation, and porphyritic feldspar lenses up to 3 by 2 inches are 
strung along in the foliation, forming in places, with biotite and 
quartz, pegmatitic bands up to 2 inches thick. One such lens con- 
tains black hornblende masses 2 inches by 1 inch. 

The plant comprises two hand derricks. 

Transportation is by cart to Amherst, about 4 miles. 

The product is used for local buildings. Specimens: Old gymnar 
sium and basement story of new geological and zoological building 
at Amherst College. 

MiDDiiESBZ coxnsnrz. 


The Harris quarry is in Acton Township, one-half mile north-north- 
west of North Acton station. (See map of Lowell quadrangle, U. S. 
Geol. Survey, and PL V.) Operator: North Acton Granite Co., 
North Acton, Mass. 

The granite (specimens D, XXX, 111, a, b), "Acton," is a biotite- 
muscovite-quartz monzonite gneiss of light bluish-gray color and of fine 
gneissic texture, with feldspars under 0.2 inch, exceptionally up to 0.3 
inch, and mica up to 0.1 inch. Its constituents, in descending order of 
abundance, are milk-white soda-lime feldspar (oligoclase), some of it 
much kaolinized, some minutely intergrown with quartz (vermicular 
structure); in nearly equal amount, clear to translucent bluish 
potash feldspar (microcline and probably orthoclase) ; clear colorless 
quartz, strained, with rutile needles and some cavities; biotite 
(black mica), some of it chloritized; and muscovite (white mica). 
Accessory: Magnetite, rather plentiful, apatite, rutile, and zircon* 

Digitized by 



Secondary: Kaolin^ epidote, carbonate, and chlorite. It effervesces 
with hydrochloric-acid test. 

This is a bright stone of sufficient coarseness to show the mineral 
contrasts, the colors being black and white. 

The quarry, opened in 1886, is 200 by 100 feet and from 10 to 36 
feet deep. The stripping, up to 10 feet thick, is of sand and bowlders. 

There are traces of sheets from 6 inches to 3 feet thick, but blocks 
12 feet thick can be obtained. This is a ''bowlder quarry.'' There 
are two sets of joints. Set a strikes N. 75° E., dips 76° S. 16° E.; 
sUckensided and coated with epidote, one only, forming the north 
wall. Set i strikes N. 36° W., dips 46° S. 66° W. to 90°; is spaced 
6 to 60 feet. The rift is about horizontal and the grain vertical with 
N. 66° E. course. Pegmatite dikes up to 6 inches thick have a 
N. 30° W. course. Busty stain is up to a foot thick on the outer 

The plant comprises two derricks, a hoisting engine, a "bull-wheel 
engine" for turning a 16-ton derrick, an air compressor (capacity, 
17^ horsepower), two air plug drills, three air hand tools, a surfacer, 
and a centrifugal pump. 

Transportation is by cart to North Acton station, half a mile. 

The product is used for buildings, monuments, and curbing, mostly 
in eastern Massachusetts. Specimens: James Wetherbee monument, 
Woodlawn Cemetery, Acton; Samuel Guilford monument, Mount 
Hope Cemetery, and Dunlop monument, Sleepy Hollow Cemetery, 
West Acton. 


The McCarthy quarry is in Acton Township, about half a mile 
northwest of North Acton station, at the top of a small knoll. (See 
map of Lowell quadrangle, U. S. Qeol. Survey, and PI. V.) Operator: 
Thomas McCarthy, North Acton, Mass. 

The granite (specimen D, XXX, 112, a), ''Acton, finer grained," 
is a biotite-muscovite-quartz monzonite of light to medium bluish- 
gray color and of fine to very fine, obscurely gneissoid texture, with 
feldspars under 0.2 inch and mica up to 0.1 inch, but mostly under 
0.06 inch. Its constituents, in descending order of abundance, are 
translucent to milk-white soda-lime feldspar (oligoclase-andesine), 
slightly kaolinized; in nearly equal amount, clear bluish potash feld-, 
spar (microcline and probably orthoclase); clear colorless quartz, 
strained, in places granulated and with cavities; biotite (black mica) ; 
and muscovite (white mica), also stringers of secondary fibrous mus- 
covite. Accessory: Magnetite, apatite, and zircon. Secondary: 
Epidote, carbonate, muscovite, and kaolin. It shows no effervescence 
with hydrochloric-acid test. 

This is a fine-grained stone without mineral contrasts and is suit- 
able for fine work. 

Digitized by 



The quarry, opened in 1890, is 150 by 80 feet and 20 feet deep. 
The stripping consists of 3 feet of loam and gravel. 

The sheets, from 6 to 16 inches thick, are horizontal or dip 10^ NE. 
There are no joints. The rift is horizontal and the grain vertical with 
northeast course. A pegmatite dike 2 feet thick on the northwest 
side is parallel to the grain. On the southeast, northwest, and south- 
west sides the granite is in contact with a quartz-mica diorite which 
is described on page 242. On the northwest side, 6 feet from the 
contact, there is an inclusion of this diorite gneiss. There is no rusty 

The plant consists of a horse derrick. Drainage is by siphon. 

Transportation is by cart to North Acton station about three- 
fourths of a mile. 

The product is used for buildings, monuments, and curbing. 
Specimens: Schoolhouse back of null on Maynard estate, Maynard, 


The Rafferty quarry is in Groton Township, 4 miles east-southeast 
of Groton village and 1^ miles northwest of West Graniteville station. 
(See maps of Groton and Lowell quadrangles, U. S. Geol. Survey, 
and PI. V.) Operator: Thomas RaflFerty, Graniteville, Mass. 

The granite (specimens D, XXX, 100, c, d), ''Groton," is a mus- 
covite-biotite granite gneiss of light to medium gray shade and of 
medium inclining to coarse gneissic, slightly porphyritic texture, with 
feldspars up to 0.5 inch and mica up to 0.1 inch. Its constituents 
appear to be identical with those of specimens 93, a, b, c, from the 
H. E. Fletcher quarry on Oak Hill, in Westf ord (p. 266) • It effervesces 
with hydrochloric-acid test. 

This stone, hke the granite gneisses of Westford, is devoid of 
mineral contrasts. It is well adapted for base courses and all work 
requiring much greater transverse strength in one direction than 
in the other and for curbing. 

The quarry, begun in a small way in 1860, and but recently reopened 
is 50 feet square, its west side being 30 feet higher than the east side. 
But one sheet has been removed. The stripping consists of 2 feet 
of soil. 

The sheets, 2 to 6 feet thick, dip 20° N. 35'' E. One joint at the 
west side strikes N. 75"* E. and dips TS"* S. IS"" E. The gneiss foliation 
is vertical, with N. 30° E. strike. The rift is horizontal and the grain 
corresponds to the foliation, the face of which is more micaceous than 
the rift face. A 30-foot inclusion of porphyritic biotite granite gneiss 
(described on p. 242) and two other smaller ones lie in the eastern 

Digitized by 



part of the quarry. The axis of the long inclusion points N. 5® E. A 
pegmatite dike up to 6 inches thick crosses the gneiss and the inclu- 
sion, as do also small dikes of aplite gneiss with oligoclase-albite. No 
stain appears below the surface sheet. 

The plant consists of three hand derricks. 

Transportation is by cart to a siding near West Graniteville station, 
1^ miles. 

The product thus far has been used for curbing. 


The Shaker quarry is in Groton Township, on an 80-foot hillock 
three-fourths of a mile north-northwest of Littleton station and 4 
miles southeast of Groton village. (See map of Groton quadrangle, 
U. S. Geol. Survey.) Operator: H. N. Fletcher, Graniteville, Mass. 

The granite (specimen D, XXX, 106, a), ''Groton,'' is a muscovite- 
biotite granite gneiss of medium bluish-gray color and slightly 
porphyritic, medium inclining to fine gneissic texture, with feldspars 
up to 0.3 inch. Its constituents, in descending order of abundance, 
are bluish translucent potash feldspar (microcUne and orthoclase); 
light smoky quartz with rutile needles and cavities, granulated, with 
particles under 0.37 miUimeter; milk-white soda-lime feldspar 
(near oligoclase-albite), kaolinized and micasized; muscovite (white 
mica), and biotite (black mica), some of it chloritized. There are 
also some fibrous muscovite stringers. Accessory: Garnet and 
apatite. . Secondary: Kaolin, two white micas, epidote, and chlorite. 
It shows no effervescence with hydrochloric-acid test. 

This stone is like the other gneisses of Groton and Westf ord, but is 
more bluish and of umform shade, without mineral contrasts. 

The quarry, temporarily idle in 1910, is of triangular form, 100 
feet on a side and from 10 to 25 feet deep. 

The sheets, from 6 inches to 3 feet thick, undulate. 

The product has been used for buildings. 


T^e. 13 active quarries of Westford are in two groups. One is on 
Oak Hill, an"irregular mass of knolls rising to a height of 200 feet 
above Merrimac River, in the northern part of the township. All 
but one of this group have their granite landing at Woods Comers 
(Slab City), on both Merrimac River and a siding of the Boston & 
Maine Railroad, 4 miles roughly west from Lowell. The other group 
is on Snake Meadow Hill, from 100 to 160 feet above the nearest 
railroads, in the southwestern part of the township. This group 
has its outlet at the Graniteville and West Graniteville stations, not 
a mile away and about 9 miles west-southwest of Lowell. (See 
PL V.) 

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The H. E. Fletcher quarry is on the southeastern part of Oak 
Hill, in Westford Township, !{ miles northwest of West Chehnsford 
station. (See map of Lowell quadrangle, U. S. Geol. Survey.) 
Operator: H. E. Fletcher Co., West Chelmsford, Mass. 

The granite (specimens D, XXX, 93, a, b, c), "Oak Hill," is a 
muscovite-biotite granite gneiss of very light, slightly bluish gray 
shade on the rift face but light gray on the grain face, and of medium, 
slightly porphyritic texture, with feldspars up to 0.3 inch and micas 
up to 0.2 inch. Its constituents, in descending order of abimdance, 
are bluish translucent potash feldspar (microcline and othoclase), 
slightly kaolinized; milk-white soda-lime feldspar (oligoclase), much 
kaolinized and with some white mica; clear colorless quartz, finely 
granulated, with particles to 0.5 millimeter, but mostly under 0.37 
millimeter, and with rutile needles and some cavities; muscovite 
(white mica) ; biotite (black mica) some of it chloritized; and stringers 
of fibrous muscovite. Accessory: Apatite. Secondary: Kaolin, 
white micas, carbonate, epidote, and chlorite. It shows very slight 
eflFervescence with hydrochloric-acid test. 

This gneiss is well adapted for base courses and all work requiring 
much greater transverse strength in one direction than in another. 
It is devoid of mineral contrasts. The absence or great scarcity of 
pyrite and magnetite is favorable to the durability of its shade. 

The quarry, opened about 1880, measures about 700 feet in a 
northeast direction by 500 feet across and from 30 to 40 feet in 
depth. The stripping consists of 5 to 10 feet of sand and bowlders. 

The sheets, 8 inches to 12 feet thick, undulate horizontally. There 
are three sets of joints. Set a strikes N. 30^-40® E., curving to N. 55® 
E., dips 70® N. 55® W. to 90®, and forms a heading on the southeast 
wall. Set I strikes N. 30® W., dips 60® N. 60® E., on southwest 
wall. Set c strikes N. 50® E., dips 65® N. 40® W., and is spaced 
300 feet and over. The gneiss foliation strikes N. 30®-40® E. and 
dips 65® N. 55® W., but appears to be crossed by a shear zone dipping 
65® about southeast. The relations of these foliations are obscure. 
The rift is horizontal, and the grain, vertical with N. 40® E. course, 
is parallel to the foliation, which shows more mica than the rift 
face. An aplite dike, 1} inches thick, bordered with half an inch 
of pegmatite on either side, has an east-west course. Pegmatite 
dikes are up to 8 inches thick. Where the granite is pegmatitic 
the mica is in crystals up to 0.4 inch across. (Specimen D, XXX, 
93, c.) The amount of limonite stain is insignificant. Mr. Fletcher 
states that he finds a compressive strain which relieves itself by an 
expansion amounting to an inch in 100 feet. 

The plant comprises 14 derricks, some of them lifting 15 tons, 12 
hoisting engines, a locomotive, a locomotive crane, 2 air compressors 

Digitized by 



(joint capacity y 2,000 cubic feet of air a minute), 60 air plug drills, 
65 air hand tools, 8 surf acers, 2 steam drills, a stone saw for steel 
shot (capacity 100 square feet an hour), a steam pump, 2 stone 
crushers with 2, 1^, and ^inch meshes and a joint daily capacity 
of 400 tons. Three 10 horsepower steam engines supply power for 
the shops, and electric power amounting to 250 horsepower is obtained 
for the quarry from Lowell. 

Transportation is by siding to Brookside station, on the Boston & 
Maine Railroad, 1} niiles. 

The fine stock produced is used for buildings and the coarse peg- 
matitic rock for bridges, paving, curbing; the waste is crushed for 
concrete. Specimens: First National Bank, Boston; granite for the 
Frick Mansion at Prides Crossing, near Beverly, Mass.; base course 
and steps of courthouse, Lowell; soldiers' monument, Plaistow, 
N. H.; 20 stories (sixth to twenty-fifth) of Bankers' Trust Co. 
building, New York; steps, base course, and approaches of post office 
and United States courthouse. New Orleans; piers for Boston Ele- 
vated Railroad to Cambridge. 


The Oak HiU quarry is near the north end of Oak Hill, in Westf ord 
Township, 6 miles west of Lowell. (See map of Lowell quadrangle, 
U. S. Geol. Survey.) Operator: Frank A. Malorey, North Chelms- 
ford, Mass. 

The granite, *'Oak Hill," is a muscovite-biotite granite gneiss of 
very light gray shade and of medium gneissic, slightly porphyritic 
texture identical with that of the H. E. Fletcher quarry, described 
on page 266. It is also useful for the same purposes as the Fletcher 

The quarry, opened about 1830, is from 700 to 1,000 feet in a 
northeast direction by 500 feet across and 40 feet deep. The stripping 
consists of 5 to 10 feet of sand and bowlders. 

The sheets, 6 inches to 8 feet thick, dip 10^ NE., but are inter- 
sected on the east wall by secondary sheets 10 to 20 feet thick, 
dipping 20*^ N. 47*^ E.* There is but one set of joints, which strike 
N. 75® E., dip 90° or steep, and are spaced on the average 60 feet. 
The gneiss foliation, shown by banding, strikes N. 40® E. The rift 
is horizontal and the grain vertical, with N. 35® E. course. The 
stone spUts better along the fohation than along the grain. There 
are dikes of pegmatite and aplite with black tourmaline. The aplite, 
consisting of potash feldspars, quartz with rutile and cavities, oligo- 
clase-albite, apatite needles, carbonate, and epidote, but no mica, 
has bands of black tourmaline 0.4 inch apart and 0.2 inch wide. 

1 Tba only other New England granite quarry in which secondary sheet structure has been observed 
Is the Fletcher quarry on Bobeeon Mountain, in Woodbury, Vt. See Bull. U. S. Qecd. Survey No. 404, 

Digitized by 



An inclusioii; 2 by 18 inches, of fine banded biotite gneiss was noticed. 
There is very little rusty stain. 

The plant comprises three derricks, two hoisting engines, two steam 
drillS; and a steam pump. 

Transportation is by cart to Woods Comers siding, about 2 miles. 

The product is used mostly for curbing and paving and finds a mar- 
ket mostly in eastern Massachusetts. 


The Peterson quarry is on Oak Hill, in Westford Township, a little 
over half a mile about north-northwest of the H. E. Fletcher quarry. 
Operators: Peterson Bros., West Chelmsford, Mass. 

The granite (specimens D, XXX, 94, a, b) is similar to that of the 
H. E. Fletcher quarry described on page 266, but a little coarser. 

The quarry, opened in 1899, is 200 feet square and 15 to 30 feet 
deep. The stripping consists of 5 or 6 feet of sand and bowlders. 

The sheets, 8 inches to 6 feet thick, dip 5^ to lO*" SE. There are 
two sets of joints. Set a strikes N. 15® to 30® E., dips steep to 90®, 
and is spaced 10 to 75 feet. Set b strikes N. 65® W., dips 60® S. 26® W., 
also N. 26® E. The gneiss foliation strikes N. 40® E. and dips 70® S. 
50® E. The rift is horizontal and grain vertical, with N. 27® E. course. 
Pegmatite dikes up to a foot thick have a N. 60° W. course. Rusty 
stain up to 6 inches thick is confined mostly to the thin sheets. There 
is a compressive strain in the grain direction. 

The plant comprises a derrick, a hoisting engine, and a steam pump. 

Transportation is by cart to Woods Comers siding, 3 miles. 

The product is used for trimmings, steps, sills, and curbing. Speci- 
mens: Trimmings on school buildings in Newton and Maiden; Massa- 
chusetts Mills, East Merrimac Street, Lowell. 


The Perley Carkin quarry adjoins the Peterson quarry on the north- 
east. Operator: Perley Carkin, North Chelmsford, Mass. 

The granite is identical with that of the Peterson quarry. 

The quarry, opened in 1905, is 400 by 200 feet and 16 to 34 feet 
deep. The stripping consists of 2 to 8 feet of sand. 

The sheets, 1 foot to 8 feet 4 inches thick, are about horizontaL 
The only joints strike N. 16® to 30® E., are vertical or steep, and are 
spaced 30 to 140 feet. Foliation, rift, and grain are the same as in 
tiie Peterson quarry. The amount of stain is small. 

The plant comprises a derrick and hoisting engine, a horse derrick, 
two landing derricks, two steam drills, and two steam pumps. 

Transportation is by cart to Woods Comers siding. If miles. 

The product is used for curbing, paving, and trimming. 

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The C. W. Carkin quarry is nearly one-quarter mile east of the 
Perley Carkin quarry. Operator: C. W. Carkin, North Chelmsford, 

The granite is identical with that of the Peterson quarry. 

The quarry is 200 by 60 feet and 10 to 15 feet deep. 

The sheets, 6 inches to 4 feet thick, are horizontal. Two joints, 
one on either side of the quarry, strike N. 30® E. Foliation, rift, and 
grain are the same as in the Peterson quarry. 

The plant consists of a horse derrick and siphon pipe. 

The product is used for curbing, paving, and trimming. 


The Cartwright quarry is on Oak Hill, in Westford Township, 
about a mile north-northwest of the H. E. Fletcher quarry and nearly 
half a mile southeast of the Oak Hill quarry. Operators: Cartwright 
Bros., Tyngsboro, Mass. 

The granite is identical with that of the quarries above mentioned. 

This is part of an old quarry reopened in 1909. It is 50 feet square 
and 5 to 10 feet deep. The sheets are 5 to 10 feet thick. 

There is one derrick and the product is used for curbing. 


The Morris & Luke quarry is in the northeastern part of Westford 
Township, about half a mile east of the Oak Hill quarry. Operators: 
Morris & Luke, North Chelmsford, Mass. 

The granite is like that of the Oak Hill quarry. 

The quarry, opened in April, 1910, is 50 feet square and has pene- 
trated only the first sheet, which is 8 feet thick. The rift is horizontal 
and the grain vertical with N. 25® to 30° E. course, but the stone spUts 
only along the rift from the hardway side even after the block is 
detached. There is an apUtic dike up to an inch thick, with a central 
band of black tourmaline and rust stains whose source is not clear. 
The plagioclase has much carbonate and the quartz has apatite 

There is a hand derrick. The product is used for curbing and pav- 
ing and carted 1^ miles to Woods Comers siding. 


The H. N. Fletcher quarries are on the top and south side of Snake 
Meadow Hill, in Westford Township, about half a mile north-north- 
west of Qraniteville station. (See map of Lowell quadrangle, U. S. 
Oeol. Survey, and PI. V.) Operator: H. N. Fletcher, Graniteville, 

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The granite (specimen D, XXX, 101, a), ''Graniteville," is a mua- 
covite-biotite-quartz monzonite gneiss of very light gray shade and of 
gneissic, medium inclining to fine, slightly porphyritic textm'e, with 
feldspars up to 0.3 inch but mostly not over 0.2 inch and micas up 
to 0.2 inch. Its constituents, in descending order of abundance, 
are milk-white soda-lime feldspar (oligoclase-albite), generally kaolin- 
ized and micasized, some with bent laminse; clear colorless quartz, 
granulated, with particles mostly not over 0.25 millimeter, and with 
rutile needles; bluish translucent potash feldspar (microcline and 
orthoclase); muscovite (white mica) and stringers of fibrous mus- 
coyite; and biotite (black mica), some of it chloritized. Accessory: 
Garnet. Secondary: Kaolin, white micas, epidote, and carbonate. 
The quartz forms a matrix of fine particles in which the feldspars lie. 
The rock shows some eflFervescence with hydrochloric-acid test. 

The gneiss in places is coarsely porphyritic (specimen D, XXX, 
101, b), of medium-gray shade with dark bluish-gray feldspars up to 
an inch square and even 2 inches by 0.75 inch. The matrix has feld- 
spars up to 0.2 inch and micas up to 0.1 inch. The feldspars are 
microperthite — potash feldspar (microcline), minutely intergrown with 
soda-lime feldspar (oligoclase-albite). 

Some of the foliation faces of the gneiss carry muscovite crystals 
(specunen D, XXX, 102, a). 

The stone of these quarries is generally lighter than that of the 
Oak Hill quarries but possesses the same general character and 

The north quarry, opened in 1906, is 250 feet square but has an 
unexcavated part 50 by 125 feet on one side. The stripping consists 
of 2 to 6 feet of clay and sand. The sheets, 1 to 6 feet thick, undulate 
horizontally. There are five sets of joints. Set a strikes N. 70° E., 
dips 45"* S. 20'' E., and is spaced 20 feet. Set I strikes N. 10° W., 
forms a heading 70 feet wide beyond the east wall. Set e strikes 
N. 20° W., dips steep to 90°, and is spaced 8 feet. Set d, vertical, 
strikes N. 10° E. Set e strikes N. 30° to 40° E., dips 70° N. 55° W. 
to 90°, forms the east wall, and is spaced 50 feet and over. The rift 
is horizontal and the grain vertical, with N. 30° E. course. The folia- 
tion is plicated, wdth a strike of N. 40° E. Pegmatite lenses occur. 

The south quarry, opened in 1860, is 200 by 150 feet and 10 to 40 
feet deep. The sheets, rift, and grain are the same as in the north 
quarry. There are two sets of joints. Set a, vertical, strikes N. 35° E., 
and is spaced 4 to 10 feet. Set h, vertical, strikes N. 75° W., and is 
spaced 3 to 6 feet. 

The plant of both quarries comprises four derricks, a hoisting 
engine, a steam drill, and a steam pump. 

Transportation is by cart to Graniteville station, one-half mile. 

The product is used mostly in ciu-bing and paving and is marketed 
in eastern Massachusetts. 

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The Palmer quarries are on the north side of Snake Meadow Hill, in 
Westford Township. (See map of Lowell quadrai^le, U. S. Geol. 
Survey.) Operator: Lewis P. Palmer, Graniteville, Mass. 

The granite of the upper quarry (specimens D, XXX, 92, b, c), 
"Graniteville," is a muscovite-biotite-quartz monzonite gneiss of 
medium-gray shade and gneissic, slightly porphyritic, medium inclin- 
ing to fine texture, with feldspar up to 0.3 inch and micas up to 0.2 
inch, rarely 0.3 inch. The stone of the lower quarry is reported as a 
little coarser than this. The constituents, in descending order of 
abundance, are grayish soda-lime feldspar, kaolinized and micasized; 
in about equal amount, bluish-gray potash feldspar (microcline and 
orthoclase), intergrown with quartz that is circular in cross section; 
light smoky quartz finely granulated with particles up to 0.25 (rarely 
0.37) millimeter, and with rutile needles and cavities; muscovite 
(white mica), some with prism faces, also fibrous muscovite stringers; 
and biotite (black mica), some of it chloritized. Accessory: Mi^et- 
ite and apatite. Secondary: Epidote, carbonate, kaolin, and white 
micas. It effervesces slightly with hydrochloric-acid test. 

This is a useful stone where greater transverse strength is required 
in one direction than in another. It is devoid of mineral contrasts 
and structurally resembles that of the Oak Hill quarries, but its shade 
is a little darker and its mineral composition slightly different. It is 
much darker than the gneiss of the H. N. Fletcher quarry. 

The upper quarry is about 300 by 215 feet and 20 to 40 feet deep. 
The stripping is 3 feet of sand. The lower quarry, 600 feet east of 
the upper, is about 200 by 100 feet and 15 feet deep. 

The sheets in the upper quarry are 1 to 5 feet thick and dip 10® 
about northeast; in lower quarry they are 2 to 7 feet thick and about 
horizontal. There are four sets of joints. Set a strikes N. 20° E., 
dips 75® N. 70® W., and forms the west waUs. Set i, vertical, strikes 
N. 35® W., and is spaced 50 feet. Set c strikes about east and west, 
dips 70® N. to 90®, and forms the north and south walls. Set d, 
vertical, strikes N. 10® W., and forms a 20-foot heading. The gneiss 
foliation strikes N. 45® to 60® E., and dips 75® SSE. to 90®. The rift 
is horizontal and the grain vertical, with northeast course like the 
foliation. The grain face is thus more micaceous than the rift face. 
There is a 12-inch dike of alternating bands of apUte and pegmatite 
with a N. 20® E. course. A fine-grained inclusion of biotite schist or 
gneiss with zoisite from this quarry has been described on page 242. 
Rusty stain is up to 3 inches thick on sheet surfaces. 

The plant comprises nine derricks, three hoisting engines, an air 
compressor (capacity 300 cubic feet of air a minute), seven air plug 
driUs, add two steam pumps. 

Digitized by 



Transportation is by cart to Graniteville station, three-fourths of 
a mile. 
The product is used for building, curbing, and paving. 


The Couture quarry lies on the west side of Snake Meadow Hill, in 
Westford Township. Operators: Couture & Son, Graniteville, Mass. 

The granite is like that of the Palmer quarries (p. 271). 

The quarry, opened in 1906, is 150 by 100 feet and 12 feet deep. 
The stripping consists of 2 to 8 feet of clay. 

The sheets, 2 to 12 feet thick, are horizontal. There are three sets 
of joints. Set a, vertical, strikes N. 10** W., and is spaced 3 to 12 feet. 
Set b strikes N. 30° E., dips 70° S. 60° E., and also N. 60° W. Set c 
strikes N. 80° E., is spaced 10 to 20 feet, coated with epidote and 
quartz crystals and slickensided, and crosses the quarry lengthwise in 
the center. Rift, grain, and foliation are as in the other quarries of 
this hill. 

The plant consists of one horse derrick and one hand derrick. 

Transportation is by cart to Graniteville station, about three- 
fourths of a mile. 

The product is used for curbing. 


The Wright quarry is on the east side of Snake Meadow Hill, in 
Westford Township. Operator: Hammett D. Wright, Graniteville, 

The granite is the same as that of the Palmer quarries (p. 271). 

The quarry, opened in 1880, is 300 by 150 feet and 15 to 20 feet 
deep. The part now worked measures about 150 by 50 feet. 

The sheets, 6 inches to 3 feet thick, are horizontal. There are 
three sets of joints. Set a, vertical, strikes N. 10° W., and forms a 
heading on the east wall. Set h strikes N. 10° E., one near west 
wall, one in center, and possibly others concealed by waste. Set c, 
steep, strikes N. 45° E., and forms the west wall. The gneiss folia- 
tions strikes N. 50° E. Pegmatite and aplite dikes up to a foot thick 
have northerly courses. 

The plant comprises two horse derricks and the product is used 
for curbing. 


The Hildreth quarry lies south of the Couture quarry, on the west 
side of the hill, in Westford Township. Operator: H. V. Hildreth, 
Westford, Mass. 

The granite is like that of the Palmer quarries (p. 271). 

The quarry, opened about 1845, is 300 by 160 feet and 10 to 40 
feet deep. 

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The sheets, 1 to 13 JEeet thick^ dip at a low angle to the north 
There am two sets of joints. Set c^ vertical or Bleep, strikes N. 10' 
E.y forms east and west walls^ and is spaced 150 feet. Set h, diseon- 
tinuous, strikes N. 50"" £., dips eO"" N. 40"^ W., forma a heading on the 
east wall, and is spaced 2 to 10 feet* Rift, grain, and foliation are 
as at the other quarries of this hill. Busty stain is up to 4 indies 
thick on sheet surfaces. 

The plant comprises two derricks, a hoisting engine, and a siphon 

The product is used for buildix^ and curbing. • 


The Barker Hill quarry is on the southwest side of that MH, about 
200 feet above the railroad in the township of Townsend, 1} miles 
north-northwest of West Townsend station and about 1{ miles north 
of West Townsend village. (See map of Groton quadrangle, U. S. 
Geol. Survey, and PI. V.) Operator: West Townsend Granite 
Syndicate, West Townsend, Mass. 

The granite (specunen D, XXX, 113, b), ''West Townsend white," 
is a biotite-quartz monzonite of very light, faintly buflf-^ray color 
and of even-grained medium inclining to fine texture, with feldspars 
under 0.3 inch, rarely over 0.4 inch, and mica up to 0.1 inch. Its 
constituents, in descending curder of abundance, are coferiess, clear 
to translucent potash feldspar (microdine), much kaohnised and 
intergrown with quartz that is circular in cross section; in neariy 
equal amount, milk-white to faint pinkish sodarlime feldspar (oligo- 
clase-albite), somewhat micasized; li^t smoky quartz with cavities 
in sheets; biotite (black mica); and a httle musoovite or Ueached 
biotite. Accessory: Magnetite, plentiful, apatite, zircon, and rutile 
(!) needles in chlorite. Secondary: Chlorite after biotite, carbon- 
ate, a white mica^ and hematite stain from the magnetite. The 
polished face shows magnetite. It effervesces with hydrochlorio- 
add test. 

A pinkirii variety (speeimensDyXXX, 113,a,d,e), ''West Townsend 
red," is of light to medium pinkish-gray shadie and of the same tex- 
ture and composition as the ''white," but the thin section shows 
pyrite and what is possibly altered allanite, with radiating cracks 
filled with hematite stain. 

This is a constructional and monumental granite of slightly coarser 
texture than the monumental granite of South Brookline, N. H., and 
probably of the same geologic age. South Brookline is only 4.4 
miles east-northeast of this quarry.^ The stone takes a good polish. 

iSee Ball U. 8. Oeol. Survey No. 430, 1910, pp. 363-363; also map of Groton quadrangle, U. 8. QeoU 

94174*— Bull. 470—11 18 

Digitized by 



The quarry, opened in 1907, is 225 by 150 feet and 5 to 15 feet 
deep. The stripping consists of 1 to 6 feet of sand and bowldeis. 

The sheets, 1 to 5 feet thick, are about horizontal. There are no 
joints. The rift is horizontal and the grain vertical, with N. 80® W, 
course. A pegmatite dike up to 4 feet thick has a N. 55® W. course. 
There are also lenses of pegmatite. ' The inclusion of biotite or diorite 
gneiss referred to on page 242 came from below the quarry. Rusty 
stain is up to 6 inches thick. 

The plant comprises four derricks and three hoisting engines, an 
air compressor (capacity 175 cubic feet of air a minute), four air plug 
drills, ten air hand tools, a surfacer, and a steam drill. 

Transportation is by cart to the railroad, one-third mile. 

The product is used mostly for buildings, but partly for monuments, 
and finds a market in New England. Specimens: Entire front of 
Thames National Bank, Norwich, Conn. ; trimmings to the following 
buildings: Alvime Memorial Chapel, Hudson, N. H.; post office, 
Nashua, N. H.; Thompson Memorial Chapel, Williams College, 
Williamstown, Mass. 




The Curry quarry is on High Rock, in Wrentham Township, about 
2i miles east^southeast of Wrentham station. (See map of Franklin 
quadrangle, U. S. Geol. Survey, and PI. V.) Operator: R. H. Curry, 
Foxboro, Mass. 

The granite (specimen D, XXX, 115, a), ^'Wrentham," is a horn- 
blende granite of light-gray shade and of even-grained medium 
inclining to coarse texture, with feldspars up to 0.5 inch and mica 
up to 0.1 inch. Its constituents, in descending order of abundance, 
are very light gray to pale cream-colored microperthite (potash feld- 
spar (microcline and orthoclase), somewhat kaolinized, minutely inter- 
grown with soda-lime feldspar) ; medium smoky quartz with abun- 
dant cavities in sheets; clear colorless to milk-white striated sodar 
lime feldspar (oligoclase-andesine), much kaolinized, also micasized 
and epidotized, in some crystals from within outward, and horn- 
blende associated with epidote. Accessory: Magnetite. Secondary: 
Kaolin, a white mica, epidote, and carbonate. It shows very alight 
eflfervescence with hydrochloric-acid test. 

This is an attractive stone with marked mineral contrasts and is 
suitable for substantial structures. 

The quarry, opened in 1884, is about 150 feet square and 25 to 
35 feet deep. The stripping is a foot of sand and soil. 

The sheets, 4 to 16 feet thick (one a foot thick), are horizontal or 
dip 15^ E. or W. and are likely to have 2 inches of decomposed granite 

Digitized by 



between them. One set of joints, vertical, strikes N. 10° E., is spaced 
2 to 100 feet, and is coated with epidote. Another set, striking N. 
60° E. and dipping 70° N. 30° W., forms headings of very close joints 
in the upper 10 feet of the rock. (See p. 246.) An obscure flow struc- 
ture dips about 65° N. The rift is horizontal and the grain vertical, 
with N. 80° W. course. "Knots" are from 1 to 6 inches across. 
Rusty stain is 2 feet thick on the top sheet. 

The plant comprises a horse derrick, a steam derrick, a hoisting 
engine, and a steam drill. 

Transportation is by cart to local customers. 

The product is used for building, curbing, and monuments. 




The Brockton Heights quarry is on Pearl Street, Brockton Heights, 
about 2i miles west of Brockton station in the same township. (See 
map of Dedham quadrangle, U. S. Geol. Survey, and PI. V.) Operator: 
Brockton Pink Granite Co., room 630, Old South Building, Boston, 

The granite (specimen D, XXX, 130, a), ''Brockton pink," is a 
biotite-homblende (or altered augite-homblende) granite of light 
greenish-gray color with large pink spots and matrix of medium tex- 
ture (feldspars up to 0.3 inch and mica up to 0.2 inch) and with por- 
phyritic light pink feldspars up to 0.8 inch. The constituents of the 
matrix, in descending order of abundance, are milk-white to greenish 
soda feldspar (albite), much micasized; clear colorless to slightly 
milky quartz with cavities in sheets; chlorite, probably after biotite 
(possibly after augite) ; a Uttle microperthite (potash feldspar (micro- 
cline), minutely intergrown with soda feldspar (albite), kaolinized, 
with epidote and zoisite in microscopic particles) ; and yellow horn- 
blende in fibrous radiating crystals. The large pink crystals are 
also microperthite and contain sparse groups of yellow hornblende 
crystals. Accessory: Magnetite and titanite. Secondary: Epidote, 
zoisite, plentiful carbonate, chlorite, a white mica, kaolin, and quartz. 
There are veinlets of carbonate, epidote, and quartz. The stone 
effervesces with hydrochloric-acid test. 

This granite is unique in New England, on account of both its tex- 
ture and its green and pink mineral contrasts. It takes a high polish. 
If obtainable in large, sound slabs it would be admirably adapted to 
interior decorative use. Physical tests are said to show that it pos- 
sesses about the same strength and hardness as Quincy granite. 

The quarry, opened in 1900, is 20 feet square and 15 feet deep. The 
areal extent of the rock is reported as about 7 acres, which probably 
only signifies the extent of the outcrops. 

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Sheet and joint structure are both defective and there is no per- 
ceptible rift or grain. 

The plant comprises a derrick^ a hoisting engine, a steam drill, 
and a stone crusher. 

Transportation is by cart to North Easton station or Brockton 
station, 2^ miles. 

The product is now confined to crushed stone, but it is hoped that 
as the quarry is deepened the rock structure may be found so much 
better that the stone can be profitably used for building. Specimen: 
Mattapan station on the New York, New Haven & Hartford Railroad 
between Dedham and Quincy, Mass. 


The Hingham seam-face quarries are in Hingham Township, 2 miles 
louth-southeast of East Weymouth station and about three-fourths 
of a mile southeast of LoveU Comers. (See map of Abington quad- 
rangle, U. S. Oeol. Survey, and PI. Y.) Operator: Hingham Granite 
& Contracting Co., 161 Summer Street, Boston, Mass. 

The granite (specimens D, XXX, 124, a, b), '^Hingham," is an 
apUte of light, slightly greenish gray color and of fine, slightly poiv 
phyritic texture, with feldspars up to 0.2 inch. Its constituents, in 
descending order of abundance, are milk-white soda-lime feldspar 
(oligodase-albite), much kaolinized and micasized and a Uttle epi- 
dotized, the alteration proceeding from within the crystals outward; 
clear, colorless quartz, with cavities, rare particles of smoky quartz up 
to 0.1 inch; pale-greenish potash feldspar (microline), a little kaolin- 
ized; very little biotite, and more of chlorite after biotite, both in 
small particles and sparse. Accessory: Pyrite, plentiful, and magnet- 
ite. Secondary: Kaolin, a white mica, chlorite, and epidote, mostly 
about the chlorite. It shows no effervescence with hydroohlorio-acid 

The following analysis of the fresh a^^e made in 1900 by F. J. 
Moore and giv^i in a report made to the company by W. O. Crosby 
and G. F. Loughlin is puUiahed here for reference: 

Analysis of aplite from Hingham, Mass. 

Saica(Si02) 74.06 

Alumina (AljOa) 14.45 

Femiw oxide (FeO) , 1.44 

Ferric oxide (FeA) 15 

Pota«h(K,0) 4.36 

Soda(NaaO) 4.74 

Lime(CaO) 1.03 

Magaeeia (MgO) Trace. 

Sulfur (8) 02 

Water (LcMS on ignition) 62 


Digitized by VjOOQIC 



Tha 0.02 per oent of sulphur is equiyalent to about 0.04 per cent of 
pyrite. Traces of manganese and j^osphoric add were noted. 

The same report giTes the following additional determinations 
made by A. A. Blanchard in 1910: 

Water below no** C 0.041 

Water above 110*»C 456 

Ctebon dioxide (CO,) 013 

Total pyrite (FeSa) 10 

Material soluble in water 08 

Material soluble in carbonic acid 13 

Tests made at the Watertown arsenal in 1910 on specimens of the 
fresh aplite show a crushing strength ranging from 32,900 to 39,800 
pounds to the square inch. Tests of the transverse breaking strength 
of the fresh aplite made for the company by Crosby and Loughlin gave 
these results: 

Results of tests of breaking strength of aplite from Eingham, Mass. 


of tests. 



Iftxinam load 





(pounds nar 

square Inch). 






2», 610-19, 430 





In comparison with these results two Watertown arsenal tests of 
Rockport granite, 4 by 8 inch beams and 19-inch span, show trans- 
verse breaking strengths of 2,404 to 2,416 pounds; and one of Milford 
(Mass.) granite, 1,745 pounds. 

Tests ol porosity and absorption made for the company by Crosby 
and Loughlin on four 3-inch cubes of the rusty aplite show from 0.285 
to 0.371 per cent or 0.04 to 0.55 gram per square inch of surface. In 
these tests the cubes were first dried at 110° C. for 24 hours, weighed, 
soaked for 48 hours in distilled water, the first two hours in boiling 
water, and then weighed again after removing excess water. Similar 
teste with two 4-inch cubes of the fresh apUte, which, however, were 
soaked for six weeks instead of two days, showed only 0.0052 gram 
per square inch of surface. 

The specific gravity of the fresh aplite was found by the same 
persona to be 2,637, which corresponds to a weight of 164.8 pounds 
per cubic foot. 

The quarries, begun many years ago for rough-faced stone but 
only in 1891 for seam-faced stone, comprise three openings. The 
largest (No. 1) is 150 feet square and 25 to 45 feet deep. No. 3, 
situated 600 feet S. 80'' E. of No. 1, is 75 by 30 feet and 10 to 20 feet 

Digitized by 



At the largest opening the sheets, which are very imperfectly 
developed and 4 inches to 6 feet thick, dip 5"" ,to 20*" NW. There 
are five sets of joints. Set a, vertical, with N. 25^ E. strike, forms a 
wide heading with joint spaces 2 inches to 2 feet 6 inches. Set b 
strikes N. 25° W., dips steep N. 65 ^^ E. and is spaced 10 to 30 feet. 
Set c strikes N. 55"* W., dips 70° N. 35° E.; only two 2 feet apart. 
Set d strikes N. 30° W., diagonal to quarry, dips steep S. 60° W. ; 
one only. Set e strikes N. 77° W., dips steep N. 13° E., and forms 
the north and south walls. 

At opening No. 3 there are no sheets whatever. Joint set a forms 
a heading in which the spacing is 8 inches to 3 feet. Set 6 has a 
dip of 75° S. 65° W. to 90° and is spaced 10 to 30 feet. Set c dips 
40° S. 35° W. 

All these sheet and joint faces are more or less stained with limo- 
nite from 0.06 to 2 inches thick, due to the oxidation of the some- 
what plentiful pyrite. There are grayish knots up to 0.5 inch, rarely 
2 by 10 inches. 

Owing to the hardness of the granite, the scarcity of sheets, the 
superabundance of joints and headings, and the prevalence of "sap" 
these would be very discouraging quarries to work for ordinary 
purposes, but in supplying the demand for rusty seam-faced stone 
their petrographic and structural features are turned to good account. 
Blocks from 4 to 15 inches thick with a seam face are used either as 
trimmings or for the main exterior, and the rough-faced unstained 
stone is used as trimmings. (See p. 247.) The following quotation 
concerns this phase of the granite industry: * 

To the ordinary uses to which granite is put, there must be added the somewhat 
recent demand for the sap portions for decorative ashlar work and rustic masonry. 
Those quarries which possess sap rock of the desirable colors are earning a new and 
adventitious revenue. In fact, the increasing demand for aeam-£aced granite and 
oth^ rocks has led to the opening of several granite quarries which produce only 
stock of this kind. The demand for seam-face granite is steadily increasing; its 
introduction is becoming more general and its artistic merits are winning better 

The plant comprises four derricks, a hoisting engine, a steam 
drill, a steam pump, and a Blondin carrier of 2 to 3 tons capacity, to 
which a stone crusher is to be added. 

Transportation is by cart either to East Weymouth station, 2 
miles, or direct to Boston, 16 miles. 

The product finds a market in eastern Massachusetts. The inter- 
section of some of the joints and sheets makes it possible to obtain a 
r^ular supply of rusty seam-faced stones with angles of 90® or 120®. 
The great crushing strength of this aplite has brought it into demand 
for keystones for tunnel arches. It is also proposed, as explained 
on page 247, to supply stones for decorative bands, in which part of 
the rusty face is to be cut away. 

1 Whittle, C. L., The building and road stones of Massachusetts: Mineral Industry, vol. 7, 1898, New 
York and I.Kmdon, 1899, p. 638. 

Digitized by 



The MUIer seam-face quarry is in Hingham Township about 21 
miles south-southeast of East Weymouth station and a mile east- 
southeast of Lovell Comers. (See map of Abington quadrangle, 
U. S. Geol. Survey.) Operator: J. E. L. Miller, East Weymouth, 

The granite (specimen D, XXX, 125, b), "Weymouth," is an aplite 
identical with that of the quarries last described and evidently 
belongs to the same mass. In thin section the biotite appears less 
altered to chlorite. 

The quarry, opened in 1901, is triangular in area, 100 feet on two 
sides and 125 feet on the other, and from 30 to 45 feet deep. 

There are no sheets, but three sets of joints. Set a, striking 
N. 25° E., forms headings with joint spaces of 2 inches to 3 feet. 
Set b, vertical, strikes N. 25° W. and is spaced 10 to 25 feet. Set c 
strikes N. 65° E. and dips 40° S. 25° E. A diabase dike, 18 inches 
thick, strikes about east and west, dipping at a steep angle to the 

The plant comprises a derrick, a hoisting engine, a steam drill, and 
a pump. 

The product, used mostly for seam-faced work, is carted to East 
Weymouth. Specimens: Gateway, Albany Rural Cemetery; Epis- 
copal churches, Holyoke and Brookline; Baptist Church, Brockton; 
Unitarian Church, Winchester; Methodist Episcopal Church, Dor- 
chester, Mass. ; bridge, Waterbury, Conn., built by the city. 

Trimmings of seam-faced aplite from one of the Hingham quarries 
are to be used in the new building of Faith Church, Springfield, Mass. 




The Black Ann Hill quarry is at the southeast foot of Black Ann 
HiD, in North Revere, that part of Revere Township which lies 
between the townships of Maiden and Saugus. (See map of Boston 
quadrangle, U. S. Geol. Survey, and PI. V.) Operators: H. & D. 
Burnett, Franklin Park, Mass. 

The rock (specimen D, XXXII, 13, a), ''Revere," is a rhyolitic 
felsite porphyry* of very dark purplish-gray color and of dense, 
apparently homogeneous texture, with very minute whitish veins and 
close joint faces coated with films of calcite. It effervesces with 
hydrochloric-acid test. Under the microscope it shows a fluidal sphe- 
rulitic banded texture, with porphyritic crystals of orthoclase (?), 
albite, and oligoclase; also particles of quartz and rare scales of 

« Determination by Dr. Whitman Cross, of the Geological Survey. 

Digitized by 



biotite and chlorite. Accessory: Magnetite and zircon. Veinlets of 
quartz and carbonate fault the feldspars. Secondary: White micas, 
epidote, carbonate, quartz, and chlorite. 

The quarry has an east-west working face 75 to 100 feet high and 
200 feet Icmg. 

A trap or diabase dike crosses the felsite from east to west, taper^ 
ing out. 

The crusher, which is on Salem Street, has meshes of f inch to H 

Transportation is by cart to a siding on the Saugus branch of 
the Boston & Maine Railroad, one-fourth mile. 

The product is used for roads and concrete material and the 
{-inch screenings and dust are sought for use in concrete in the place 
of sand. This quarry supplied over 61,000 tons of crushed felsite 
for the construction of the East Boston tunnel and 21,000 tons to 
the United States Engineer Corps in 1898 for the construction of 
the battery at Fort Heath, in Winthrop. The dust was also used 
in 1908 in the concrete of two large schoolhouses, three fire-engine 
stations, two city stables, the hospital, and the armory in Chelsea. 

H. A. Carson, chief engineer of the Boston Transit Commission, 
had the relative value of the dust of this felsite (with f -inch screen- 
ings) and of sand, for concrete, tested in beams of 30-inch span, 
with these results: ^ 

Tut cf/BUiU dust and amdfor {xmerete. 


of rup- 

B4Winff with imnd .... , . . ^ ^ . » - - - 



DMina wfth rAlifft* ripfft , , ., .- 





The McCauliff quarry is on the west side of Rollstone Hill in Fitch- 
burg,' a mile a little south of west of the Boston & Maine Railroad 
station. (See map of Fitchburg quadrangle, U. S. Geol. Survey, 
and PL V.) Operator: F. A. McCauliff, 37 River Street, Fitchburg, 

The granite (specimen D, XXX, 107, a), "Fitchburg," is a musco- 
vite-biotite granite gneiss of light to medixmi bluish-gray color and 

I See report o( ohief eagtueer, In Sorenth Ann. Rept Boston Tnmslt Comm., Au(. 15, 1901, Appendix 
A, p. 41. 

* This hill takes Its name from a glacial bowlder, 10 by 8 feet of granitic rock, with 3-lnoli poxphyiitio 
CiTstals, which lies on Its top. The hill Itself appears to be a granite dome. 

Digitized by 



of gneissic medium texture, with feldspars up to 0.3 iach and micas 
up to 0.2 inch. Its constituents, in descending order of abundance, 
are bluish dear to translucent potash feldspar (microcline and 
orthoclase); li^t smoky quartz, finely granulated (particles under 
0.37 millimeter), with rutile needles and cavities; milk-white soda- 
lime feldspar (oligoclase-albite), kaolini^ed and micasized; mus- 
covite (white mica) and fibrous musoorite in stringers; and biotite 
Cblack mica), some of it chloritized. Accessory: Garnet and apatite. 
Secondary: Kaolin, white micas, epidote, and chlorite. It shows 
no eflfervescence with hydrochloric-acid test. 

This is a constructional granite gneiss of bright mineral contrasts. 

The quarry, opened about 1865, in triangular in area, measuring 
about 450 feet on its north side and 175 feet on its east side, which 
are the working faces, and is 10 to 20 feet deep. 

The sheets, 1 to 8 feet thick, horizontal at the northeast comer 
of the quajrry, dip away radially to an angle of 15^ in its lower part. 
There are four sets of jomts. Set a strikes N. 75® W. to N. 75** E., 
dips 65® about south, forms the north wall, is spaced 3 to 20 feet, 
and the joints are tight and ferruginous. Set &, Tertical, strikes N. 
5® W.; only a few. Set c strikes N. 60® E., dips 75® S. 30® E., is 
spaced 12 feet and over; few and loose. Set d strikes N. 20® W., 
dips 45® S. 70® W.; three only, 20 to 150 feet apart. The gneiss 
foliation strikes N. 10® E. and dips 55® N. 80® W. The rift is hori- 
zontal and the grain Tertical, with N. 80® E. course. There are a 
number of pegmatite dikes up to 4 inches thick, with black tourma- 
line dipping 45® about north and spaced 15 feet and over. Some of 
these dikes meander and combine. One is faulted along a N. 20® E. 
plane. Another has a half-inch central band of smoky quartz and 
borders of feldspar and tourmaline. The stone is generally sound 
except near the main joints and for 2 or 3 inches along sheet surfaces. 

The plant comprises four derricks, four hoisting engines, an air 
comprassor (capacity 690 cubic feet of air a minute), fifteen air plug 
driUs, four surfacers, two large rock driUs, and a stone crusher 
with screens of 2^, 1^, and i inch meshes, and has a daily capacity of 
90 tons. 

Trai»portation is by cart to the railroad siding, one-eighth mile. 

The best of the product is used for base courses, the seconds for 
curbing and paving, and the waste for concrete. Its market is 
chiefly locaL Specimen: First story of high school, Fitchburg. 


The Litchfield quarry is on the southwest side of Rollstone Hill in 
Fitchburg, nearly a mile west-southwest of the Boston & Maine Bail- 
road station. (See map of Fitchburg quadrangle, U. S. Geol. Survey, 
and PL V.) Operator: O. E. Litchfield, Fitchburg, Mass. 

Digitized by 



The granite is identical with that of the McCanliff quarry, described 
on page 280. 

The quarry, opened in 1875, triangular in area, is 700 feet (originaUy 
1,000 feet) in a northerly direction by 200 feet and 76 feet. 

The sheets, 6 inches to 6 feet, some 15 feet thick, curve gently west- 
ward from the top of the hill. There is but one set of joints, which 
strike N. 70° E., dip 45° S. 20° E.; two only, 50 feet apart, discon- 
tinuous. Foliation, rift, and grain are as at the McCauliff quarry. 
Pegmatite dikes up to 6 inches dip 50° NE. At the southeast end 
is one, 2 feet thick^ of smoky quartz, feldspar, muscovite, and black 
tourmaline. Some of these dikes are very micaceous, becoming the 
''sand seams'' of quarrymen. The "sap" is 6 inches thick on the 
top sheets. 

The plant comprises six derricks, two hoisting engines, a 50-horBe- 
power air compressor, six air plug driUs, three stream drills, and a 
stone crusher with 2^, 1^, and f inch meshes, and has a daily capac- 
ity of 200 tons. 

The product is used for dimension stone, curbing, and paving. 
The smallest size from the crusher is used for graveling roofs. Speci- 
mens: Wallace Way, steps and buttresses to high school, and most 
of the stone in Episcopal Church chapel, Fitchburg. 


The Godbeer quarry is on the northeast side of RoUstone HiU, in 
Fitchburg, about three-fourths of a mile west of the Boston & Maine 
Railroad station. (See map of Fitchbui^ quadrangle, U. S. Geol. 
Survey, and PL V.) Operator: Henry Godbeer, Fitchburg, Mass. 

The granite is identical with that of the McCauliff quarry, described 
on page 280. 

The quarry is 250 feet in a northeast direction by 200 feet across 
and 5 to 10 feet deep. 

The sheets, 1 to 8 feet thick, dip 20° NE. Their variation in 
thickness is due to incomplete formation, '' growing on." There 
are three sets of joints. Set a, vertical, strikes N. 40°~60° E., is 
spaced 10 to 20 feet, and has rusty faces. Set h strikes N. 80° E., 
dips 55° S. 10° E. ; few. Set c strikes N. 60° W., dips 40° S. 40° W. ; 

The plant comprises three derricks, two hoisting engines, an air 
compressor (capacity 210 cubic feet of air a minute), four air plug 
drills, a surf acer, and three steam drills. 

Iransportation is by cart to the railroad siding, half a mile. 

The product is used lor building and curbing. Specimen: Third 
story of Moran Building, Fitchburg. 

Digitized by 




The Leavitt quarry is in the township of Leominster, 2 miles west 
of that village and about 400 feet above it. (See map of Fitchburg 
quadrangle, U. S. Geol. Survey, and PI. V.) Operators: F. M, Leavitt 
& Ck)., Leominster, Mass. 

The granite (specimen D, XXX, 110, a), '^Leominster," is a mica 
diorite of dark bluish-gray shade (between ''Barre dark" and "Quincy 
extra dark") and of very fine even-grained texture with particles 
imder 0.1 inch. Its constituents, in descending order of abundance, 
are light-grayishsoda-lime feldspar (oligoclase-andesine) ; biotite (black 
mica), with rare muscovite or bleached biotite; and very Ught smoky 
quartz. Accessory: Titanite (fourth in order of abimdance), plentiful 
apatite needles, zircon crystals in strings, also branching, and pyrite. 
Secondary: Carbonate and chlorite. It effervesces with hydro- 
chloric^acid test. 

This is a handsome fine-grained dark stone, suitable for monuments 
or buildings. It ought to hammer light. 

The quarry, opened in 1870, is 300 feet north and south by 200 
feet across, and 5 to 30 feet deep. 

The sheets, 6 inches to 5 feet thick, but mostly imder 18 inches, 
dip 20° E. There are two sets of joints. Set a, vertical, strikes N. 
80° E. and forms the south wall. Set h, vertical, strikes N. 5° E., 
dips steeply east to 90°, and forms the east and west walls. The rift 
is parallel to the sheets and the grain vertical north to south. The 
quarry is crossed diagonally by a large ramifying dike of banded 
aplite and pegmatite which is described on page 242 and a horizontal 
section of which is shown in figure 38, p. 243. Minor dikes of aplite and 
also of pegmatite intersect the main dike. One 4 feet 6 inches thick 
is on the west wall. The diorite also has here and there white feldspar 
"knots" up to 1.5 inches across. 

The plant comprises a derrick, a hoisting engine, and a steam drill. 

Transportation is by cart to Leominster station, 2i miles. 

The product is used for buildings, trimmings, curbing, flagging, 
and foimdations and has a local market. Specimens: Haws Memorial 
C!hapel in Evergreen Cemetery; trimmings to Mayo and Jones blocks, 
Leominster; and trimmings to Acre School, Clinton, Mass. 


The Blanchard quarries are in Uxbridge Township, about 1 J noiles 
west-northwest of Uxbridge station and If miles south-southeast of 
Whitinsville. (See map of Blackstone quadrangle, U. S. Geol. Survey, 
and PI. V.) Operators: Blanchard Bros. Granite Co., Linwood, Mass. 

Digitized by 



The granite (specimens D, XXX, 114, d, e), '^Uxbridge," is a biotite 
granite gneiss of light to medium gray shade Qight gray on rift face 
and medium gray on hardway face) and of medium porphyritic, 
elongated gneissic texture, with feldspars up to 0.4 inch (exception- 
ally 0.5 inch) and lainin» of quartz and mica up to 0.1 inch wide, 
alternating with laminaB of feld^ar up to 0.3 inch wide. Its constitu- 
ents, in descending order of abundance, are light-buff potash feldspar 
(microcline and orthoclase), slightly micasized; light smoky quartz 
with cavities in parallel and rectangular sheets; milk-white soda- 
lime feldspar (oKgoclase) ; biotite (black mica) ; and a little muscovite 
or bleached biotite. Accessory: Magnetite, apatite, and purple 
fluorite. Secondary: Carbonate, epidote, kaolin, and muscovite. It 
effervesces slightly with hydrochloric-acid test. 

This gneiss resembles that of 
Sterling, Conn., and is a useful 
constructional stone. 

The quarries, begun in 1864, 
consist of two openings. The 
larger is 300 by 200 feet and 20 
to 50 feet deep, and the smaller, 
triangular in area, 100 feet on a 
side and 60 feet deep in the cen- 
ter. The stripping consists of 2 to 
10 feet of gravel and bowlders. 

As sheet structure is absent 
this is a "bowlder quarry." The 
courses of the joints, foliation, 
etc., are shown in figure 42. Joint 
W. and is spaced 5 to 40 feet. Set h dips 30"* N. 
45°-60^ E. and is spaced 3 to 20 feet. Set c dips 55^ S. 72** W. and is 
spaced 10 to 60 feet. The foliation dips 35** N. 70** E. The rift dips 
10°-15® N. 20** E. and the grain and hardway are vertical. Aplite 
dikes are 2 inches to 3 feet thick. Pegmatite dikes of banded quartz 
and feldspar (described on p. 245) parallel to joints c are up to 3 feet 
thick, and an amphibolite dike (described on p. 243) parallel to joints h 
is 6 to 18 inches thick. The amount of sap varies greatly. Some 
blocks are free from it, some are all stained, on others it is a foot thick. 
The plant comprises eight 10-ton derricks, four smaller ones, eight 
hoisting engines, a 16-ton locomotive, an air compressor (capacity 
396 cubic feet of air a minute), nine air plug drills, two air hand tools, 
two surfacers, a hand surfacer, three steam drills, and a stone crusher 
with adjustable meshes and a daily capacity of 35 tons. 

Transportation is by a private siding to the New Yoit, New Haven 
& Hartford Railroad, 1^ miles. 

at Bteodiatd quante, 
Uxbdd^e, liaas. 

set a dips 77** S. 38' 

Digitized by 



The product is used for buildings and bridges, the waste for foun- 
dations, paving, and crushed stone for concrete. Its market is east- 
em Massachusetts. Specimens: Tower and stonework of St. Charles 
Roman Catholic Church, Woonsocket, R. I. ; trimmings of city hospital. 
Providence, R. I.; trimmings of New York, New Haven & Hartford 
Railroad station at Attleboro, Mass.; and of Holmes Manufacturing 
Co.'s mill. New Bedford, Mass. ; town bridge over Quinebaug River 
at Southbridge, Mass. ; and a number of bridges for the New York, 
New Haven & Hartford Railroad in eastern Massachusetts. 


The prices ciurent in 1910 of two of the granites described here may 
be of service in placing them commercially: Oak Hill (Westford) 
granite gneiss, dimension stock, in the rough, f. o. b., per cubic foot, 
30 to 40 cents; FaU River gnebsoid gramte, same stock, etc., 40 cents. 



In the following table all the ''granites" described, as well as all 
the other commercial granites of Massachusetts described in Bulletin 
354, are classified according to their uses and are also designated by 
their scientific and trade names. This table thus gives a survey of all 
the commercial granites of the State. Where a granite is used for 
two purposes it is repeated in the grouping. 

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As appears from the foregoing table, the variety of Massachusetts 
granites is wide considered either scientifically or eoonomicaUy. 
They include hornblende granites, hornblende-augite granites, rie- 
beckite-SBgirite granite, quartz monzonite and quartz monzomte 
gneisses, biotite granite gneisses, biotite and muscovite granite 
gneisses, aplite, mica diorite, and diabase porphyry. They vary 
greatly not only in texture — from granitic to gneissic, coarse to very 
fine — ^but also in color and shade — some are pinkish; others pea- 
greenish, olive-greenish, gray of various shades, from li^t to very 
dark, besides grays of slight bluish, purplish, or greenish tinge; one 
is brown. 

The most marked for their adaptation are the massive construc- 
tional granites of Milford, Fall River, New Bedford, and Rockport; 
the poUsh granite of Quincy; the hard paving granite of Rockport; 
the gneisses for bridges, base courses, curbing, and sills of Monson, 
Westford, Fitchburg, and Uxbridge; and the Hingham aplite for 
seam-faced work and for structures in which unusually great crushing 
or transverse strength are required. 

Among the more notable works of Massachusetts granite are the 
Pennsylvania Terminal in New York and the McKinley Memorial 
at Canton, Ohio (Milford); the Boston and Baltimore post offices 
(Rockport) ; the Army and Navy training stations at Newport, R. I. 
(Fall River); Bunker Hill Monument, the large polished balls at 
Rock Island, 111., and Fairmount Cemetery, Newark, N. J., and the 
Whitney monument at Woodlawn Cemetery, New York (Quincy). 

Digitized by 



The following list comprises the more important recent publications 
on building stone and road metal by the United States Geological 
Survey. These pubUcations, except those to which a price is affixed, 
can be obtained free by applying to the Director, United States 
Geological Survey, Washington, D. C. The priced pubUcations may 
be purchased from the Superintendent of Documents, Govemment 
Printmg Office, Washington, D. C. The annual volumes on Mineral 
Resources of the United States contain not only statistics of stone 
production, but occasional discussions of available stone resources 
in various parts of the country. Many of the Survey's geologic foUos 
also contain notes on stone resources that may be of local importance. 

Alden, W. C. The stone industry in the vicinity of Chicago, 111. In Bulletin 
213, pp. 357-360. 1903. 25c. 

Baik, H. F. Notes on Iowa building stones. In Sixteenth Ann. Rept., pt. 4, 
pp. 500-503. 1895. $1.20. 

BuBCHARD, £. F. Structural materials available in the vicinity of Minneapolis, 
Minn. In Bulletin 430, pp. 280-291. 1910. 

Structural materials available in the vicinity of Austin, Tex. In Bulletin 

430, pp. 292-^16. 1910. 

Stone. In Mineral Resources United States for 1909, pt. 2, pp. 569-608. 


Coons, A. T. Slate. In Mineral Resources United States for 1909, pt. 2, pp. 557- 
568. 1911. 

Dalk, T. N. The slate belt of eastern New York and westem Vermont. In 
Nineteenth Ann. Rept., pt. 3, pp. 153-200. 1899. $2.25. 

The slate industry of Slatington, Pa., and Martinsburg, W. Va. In 

BuUetin 213, pp. 361-364. 1903. 25c. 

Notes on Arkansas roofing slates. In Bulletin 225, pp. 414-416. 1904. 35c. 

Note on a new variety of Maine slate. In Bulletin 285, pp. 449-460. 

1906. 60€. 

The granites of Maine. Bulletin 313. 202 pp. 1907. 

The chief commercial granites of Massachusetts, New Hampshire, and 

Rhode Island. Bulletin 354. 228 pp. 1908. 

The granites of Vermont. Bulletin 404. 138 pp. 1909. 

Supplementary notes on the granites of New Hampshire. In Bulletin 430, 

pp. 346-372. 1910. 

Dale, T. N., and others. Slate deposits and slate industry of the United States. 
BuUetin 275. 154 pp. 1906. 15c. 

Dartom, N. H. Marble of White Pine County, Nev., near Gandy, Utah. In 
BuUetin 340, pp. 377-380. 1908. 

Structural materials in parts of Oregon and Washington. BuUetin 387. 

36 pp. 1909. 

94174*"— Bull. 470—11 19 289 

Digitized by 



DiLLBBy J. S. Limestone of the Redding district, California. In Bulletin 213, 
p. 365. 1903. 25c. 

EcKBL, £. 0. Slate deposits of California and Utah. In Bulletin 225, pp. 417-422. 
1904. 35c. 

Gardner, J. H . Oolitic limestone at Bowling Green and other places in Kentucky. 
In Bulletin 430, pp. 373-378. 1910. 

HiLLEBRAND, W. F. Chemical notes on the composition of the roofing slates of 
eastern New York and western Vermont. In Nineteenth Ann. Rept., pt. 3, pp. 
301-305. 1899. $2.25. 

Hopkins, T. C. The sandstone of western Indiana. In Seventeenth Ann. Rept., 
pt. 3, pp. 780-787. 1896. 

Brownstones of Pennsylvania. In Eighteenth Ann. Rept., pt. 5, pp. 

1025-1043. 1897. 

Hopkins, T. C, and Siebbnthal, C. E. The Bedford oolitic limestone of Indiana. 
In Eighteenth Ann. Rept., pt. 5, pp. 1050-1057. 1897. 

Humphrey, R. L. The fire-resistive properties of various building materials. 
Bulletin 370. 99 pp. 1909. 

Keith, A. Tennessee marbles. In Bulletin 213, pp. 366-370. 1903. 25c. 

Leiohton, Henry, and Bastin, E. S. Road materials of southern and eastern 
Maine. Bulletin 33, Office of Public Roads, Department of Agriculture. 1908. 
(May be obtained from Department of Agriculture.) 

Paiob, Sidney. Marble prospects in the Chiricahua Mountains, Arizona. In 
Bulletin 380, pp. 299-311. 1909. 

Mineral resources of the Llano-Burnet region, Texas, with an account of 

the pre-Cambrian geology. Bulletin 450. 103 pp. 1911. 

Purdue, A. H. The slates of Arkansas. In Bulletin 430, pp. 317-334. 1910. 

RiES, H. The limestone quarries of eastern New York, western Vermont, Massa- 
chusetts, and Connecticut. In Seventeenth Ann. Rept., pt. 3 (continued), pp. 
795-811. 1896. 

Shaler, N. S. Preliminary report on the geology of the common roads of the 
United States. In Fifteenth Ann. Rept., pp. 25^306. 1895. 

The geology of the road-building stones of Massachusetts, with some con- 
sideration of similar materials from other parts of the United States. In Sixteenth 
Ann. Rept., pt. 2, pp. 277-341. 1895. $1.25. 

SiEBENTHAL, C. £. The Bedford oolitic limestone [Indiana]. In Nineteenth Ann. 
Rept., pt. 6, pp. 292-296. 1898. 

Smith, G. 0. The granite industry of the Penobscot Bay district, Maine. In 
Bulletin 260, pp. 489-492. 40c. 

Udden, J. A. The oolitic limestone industry at Bedford and Bloomington, Ind. 
In Bulletin 430, pp. 335-345. 1910. 

Watson, T. L. Granites of the southeastern Atlantic States. Bulletin 426. 282 
pp. 1910. 

Digitized by 




The following list includes the principal pubUcations on cement 
materials by the United States Geological Survey, or by members of 
its staff. The Government publications, except those to which a 
price is aJBSxed, can be obtained free by applying to the Director, 
United States Geological Survey, Washington, D. C. The priced 
pubUcations may be purchased from the Superintendent of Docu- 
ments, Government Printing Office, Washington, D. C. 

Adams, 6. 1., and others. Economic geology of the lola qnadiaogle, Kansas. Bul- 
letin 238. 80 pp. 1904. 

Ball, S. H . Portland cement materials in eastern Wyoming. In Bulletin 315, pp. 
232-244. 1907. 

Bassler, R. S. Cement materials of the valley of Virginia. In Bulletin 260, pp. 
531-544. 1905. 40c. 

Burchard, E. F. Portland cement materials near Dubuque, Iowa. In Bulletin 
315, pp. 225-231. 1907. 

Concrete materials produced in the Chicago district. In Bulletin 340, pp. 

383-410. 1908. 

Structural materials available in the vicinity of Minneapolis, Minn. In 

Bulletin 430, pp. 280-291. 1910. 

Structural materials available in the vicinity of Austin, Tex. In Bulletin 

430, pp. 292-316. 1910. 

The cement industry in the United States in 1909. In Mineral Resources 

U. S. for 1909, pt. 2, pp. 433-462. 1911. 

Butts, C. Sand-lime brickmaking near Birmingham, Ala. In Bulletin 315, pp. 
256-258. 1907. 

Canister in Blair Count>', Pa. In Bulletin 380, pp. 337-342. 1909. 

Catlett, C. Cement resources of the valley of Virginia. In Bulletin 225, pp. 457- 

461. 1904. 35c. 

Clapp, F. G. Limestones of southwestern Pennsylvania. Bulletin 249. 52 pp. 

Crider, a. F. Cement resources of northeast Mississippi. In Bulletin 260, pp. 
610-521. 1905. 40c. 

Geologyand mineral resources of Mississippi. Bulletin 283. 99 pp. 1906. 

Darton, N. H. Geology and water resources of the northern portion of the Black 

Hills and adjoining r^ons in South Dakota and Wyoming. Professional Paper 65. 
104 pp. 1909. 

Structural materials in parts of Oregon and Washington. Bulletin 387. 36 

pp. 1909. 

Cement materials in Republican Valley, Nebraska. In Bulletin 430, pp. 

381-387. 1910. 


Digitized by 



Daston, N. H., and Sibbkmthal, G. E. Geology and mineral resourceB of the 
Laiamie Basin, Wyoming. Bulletin 364. 81 pp. 1908. 
DuRTBE, E. Cement investigationB in Arizona. In Bulletin 213, pp. 372-380. 

1903. 25c. 

Eckel, B.C. The materials and manufacture of Portland cement. In Senate Doc. 
19, 58th Cong., Ist sees., pp. 2-11. 1903. 

Cement-rock deposits of the Lehigh district. In Bulletin 225, pp. 448-450. 

1904. 35c. 

Cement materials and cement industries of the United States. Bulletin 

243. 395 pp. 1905. Edition exhausted. Available for reference in libraries of 
cities and educational institutions. 

The American cement industry. In Bulletin 260, pp. 496-505. 1905. 40c. 

Portland cement resources of New York. In Bulletin 260, pp. 522-530. 

1905. 40c. 

Cement resources of the Cumberland Gap district, Tennessoe-Viiginia. In 

Bulletin 285, pp. 374-376. 1906. 60c. 

Eckel, E. C, and Crider, A. F. Geology and cvment resources of the Tombigbee 
River district, MiBsissippi-Alabama. Senate Doc. 165,''58th Cong., 3d sess. 21 pp. 

Humphrey, R. L. The effects of the San Prancidco earthquake and fire on various 
structures and structural materials. In Bulletin 324, pp. 14-61. 1907. 50c. 

Organization, equipment, and operation of the structural-materials testing 

laboratories at St. Louis, Mo. Bulletin 329. 85 pp. 1908. 

Portland cement mortars and their constituent materials: Results of tests, 

1905 to 1907. Bulletin 331. 130 pp. 1908. 25c. 

The strength of concrete beams; results of tests made at the structural- 
materials testing laboratories. Bulletin 344. 59 pp. 1908. 

The fire-resistive properties of various building materials. Bulletin 370. 

99 pp. 1909. 

Landes, H. Cement resources of Washington. In Bulletin 285, pp. 377-383. 

1906. 60c. 

Martin, G. C. The Niobrara limestone of northern Colorado as a possible source of 
Portland cement material. In Bulletin 380, pp. 314-326. 1909. 

Pepperberg, L. J. Cement material near Havre, Mont. In Bulletin 380, pp. 
327-336. 1909. 

Richardson, G. B. Portland cement materials near £1 Paso, Tex. In Bulletin 
340, pp. 411-414. 1908. 

Russell, I. C. The Portland cement industry in Michigan. In Twenty-second 
Ann. Rept., pt. 3, pp. 620-686. 1902. 

Sewell, J. S. The effects of the San Francisco earthquake on buildings, engineer- 
ing structures, and structural materials. In Bulletin 324, pp. 62-130. 1907. 50c. 

Shaw, £. W. Gxavel and sand in the Pittsburg district, Pennsylvania. In Bulle- 
tin 430, pp. 38^-399. 1910. 

Smith, E. A. The Portland cement materials of central and southern Alabama. 
In Senate Doc. 19, 58th Cong., Ist sess., pp. 12-23. 1903. 

Cement reeouicee of Alabama. In Bulletin 225, pp. 424-447. 1904. 35c. 

Taff, J. A. Chalk of southwestern Arkansas, with notes on its adaptability to the 

manufacture of hydraulic cemants. In Twenty-second Ann. Rept, pt. 3, pp. 687- 
742. 1902. 

Digitized by 



By G. B. RiOHABDsoK. 

A deposit of clay has recently been exploited near Calhan, El Paso 
CJounty, Oolo.y a town on the Chicago, Rock Island & Pacific Railway 
39 miles east of Colorado Springs. The deposit is situated between 
1^ and 3 miles east and south of the railroad station at Calhan. The 
clay is of good grade, Is easy of access, and can readily be worked in 
open pits. 

Calhan is situated near the Platte-Arkansas divide, in the south-cen- 
tral part of a broad sTuoline known as the Denver Basin. The rocks are 
all sedimentary, and the strata lie practically flat. Big Sandy Creek 
has cut down to the coal-bearing rocks of probable Laramie age, which 
come into contact with the overlying formation in the immediate 
vicinity of Calhan. The rocks above the coal-bearing strata are com- 
posed chiefly of arkose derived from the granite of the Front Range, 
and the clay deposits constitute a local member of these rocks. They 
are of Eocene age, but to what subdivision of the Eocene they belong 
has not yet been determined, although a nxunber of fossil leaves have 
been collected from them. In an escarpment northwest of Calhan 
the Eocene rocks are unconformably overlain by conglomerate and 
sandstone of Oligocene age which contain Titanotherium bones. 
Southeast of Calhan erosion has carried away the upper beds, and the 
arkose and associated clays are overlain by unconsolidated gravel 
and sand, of late Tertiary or Quaternary age, which consitute the 
surface of the upland for many miles to the south. 

The clay occupies a zone about 100 feet thick and outcrops in a 
northwestward-facing escarpment east and south of Calhan. The 
deposits are exposed for a distance of 3 or 4 miles, but how far back 
into the hills they extend has not been determined, although their 
occurrence probably is not widespread. The clays are stratified and 
are sorted, water-laid material which apparently accumulated in 
local bodies of water in contrast with much of the arkose, most of 
which is of subaenal origin. The composition, occurrence, and asso- 


Digitized by 



elation of the clay indicate that it is slightly transported residual 
material derived from the decomposition of granitic feldspars. 

The clay is varied in texture and color, but development has not 
gone far enough to indicate the extent of the variations. In texture 
the clay ranges from extremely fine to coarse grained, and the colors 
are gray, buff, brown, red, purple, yellow, and mottled. In places it 
is difficult to get much of any one grade, but selected areas show 
homogeneoxis material several feet thick. Apparently little attention 
has yet been given to sorting the clay at the pits, the material being 
carted off as it is quarried. 

Tests of five specimens of clay selected to represent different 
grades of the Calhan deposits were made by the Bureau of Standards. 

The sample was first ground in a porcelain mortar, then tempei^d 
with a sufficient amount of water to render it plastic and molded by 
hand into small briquets, 3 inches by 1 inch by one-fourth inch, 
lines 5 centimeters apart were marked off on the wet pieces by means 
of a vernier caliper, and from these lines the drying and burning 
shrinkages were measured. The briquets were dried in the open air. 
The samples were burned in a down-draft, gas-fired test kiln to 
1,2)0^ C, the duration of the burning being 48 hours. The melting 
points were determined in an electric furnace, a test cone 1 inch in 
height serving as the test piece for each clay. 

Digitized by 






































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Inspection of the table ahowa th^t the Calhan deposits are of good 
grade clay adapted for various purposes. The plasticity of all the 
samples except C is good, and most of the clay, therefore, can be 
readily molded. Sample C is not plastic and is what is known as 
flint clay, which is unsuitable for stiff-mud working. All the samples 
show excellent drying behavior, neither warping nor cracking. The 
burning color varies with the iron content. Sample B bums to a 
good red color; the others bum buff or white, and are therefore valu- 
able for face brick, etc. The fusibility of all is high, that of sample 
B (the red-bumiiig variety) being the lowest, while that of samples C 
and D is very high, classing them with high-grade refractory clays. 

Chemical analyses were made of only two samples — ^A and C. They 
show that both clays are essentially hydrated silicates of aluminum 
with small amounts of other substances. The analyses, especially 
that of sample C, show a close approach to the ndneral kaolinite, 
which is the basis of ''pure clay." The sum of the fluxing impuri- 
ties — ^iron oxide, lime, magnesia, soda, and potash — ^is low, indicating 
high refractoriness. The notable amount of titanium oxide (more 
than 1 per cent in each analysis) suggests the presence of rutile, an 
accessory mineral of granite, which is not uncommon in clays derived 
from the decomposition of granitic rocks. 

Statistics of the quantity of clay mined at Calhan are not available. 
It is reported that the deposits were first worked in 1903 and that 
recently shipments have increased. Practically all of the clay is 
sent to Pueblo, 84 miles distant, where it is reported to be used for 
making retorts, lining the insides of fumaces, converter bottoms, 
cupola linings, fire brick for buildings, sewer pipe, etc. The Calhan 
day is adapted also for the uses suggested by the table of tests. 

Digitized by 




By E. W. Shaw. 


The Murphysboro quadrwigle embraces au area of about 13 by 17 
miles, in the southwestern part of Illinois. Its boundaries are paral- 
lels and meridians and it includes parts of Jackson and Perry counties. 
The principal towns are Murphysboro^ with 6^463 inhabitants^ Ava, 
and Vergennes. The area is crossed by several railroads and no 
point in it is more than 6 miles from a railroad track. 

The quadrangle Ues within a region in which there are extensive 
clay resources and a large demand for clay products, yet it does not 
contain many manufacturing plants. Most of the clay deposits of 
the quadrangle outcrop in a curved belt ej^tending eastward across 
the south end of the State and northward toward St. Xx>uis, so that the 
brief description here given will apply in a general way to a much 
larger territory. 

More than half of the area included in the Murphysboro quadrangle 
lies in the great low plain of southern BlinoiSi but the southwestern 
part of the quadrangle is within the belt of hills which cross the 
southern part of the State and are known locally as the Osarks. The 
extreme southwest comer includes about 3 square miles of the Missis- 
sippi bottoms. 



The strata lying near the surface in the Murphysboro quadrangle 
consist of more or less consolidated shale, clay, sandstone, limestone, 
and coal belonging to formationa of the Carboniferous system, and 
unconsolidated clay, sand, and gravel of Quaternary age. A gener- 
alized section of the principal groups of strata showing their relation 
to each other is given below: 

Section of rods in Mi^physhoro qiuidrangle, 

Quatemaiy ayetem : 7«et. 

12. Becent alluviuin, viprying from gravel to clay 10 

11. Loess, extremely fine sand or clay 15-50 

10. Valley filling — dark-gray limy clay, aandy in places. . . 1-125 

9. Glacial till—gravfUy day 10 

9. Preglacial alluvium and decayed rock— clay, more or 

less gravelly , 10 


Digitized by 



Carboniferous system: 
Pennsylvanian series: 

Post-Pottsville rocks: Feet. 

7. CoalNo.6 6 

6. Underclay 0-6 

5. Shale and sandstone, witJi several lenticular 

beds of limestone and coal 175-225 

4. Sandstone, soft, micaceous 10-65 

3. Shale, soft, gray, with bed of coal near top 20-135 

2. CoalNo.2 4 

Pottsville formation: 

1. Sandstone, hard, gray or buff, mostly massive, 
nonmicaceous; locally conglomeratic, particu- 
' larly near the top, and containing lenses of 
shale and coal at several horizons 400-500 

From the above section it will be seen that the Pottsville consists 
largely of resistant sandstone with a subordinate amount of shale, 
whereas the higher or younger Pennsylvanian rocks and the Quater- 
nary are composed of softer material, of which clay and shale of 
various kinds make up a large part. 


The structure of the consolidated rocks is dominated by an uplift in 
the southwestern part of the area, which gives rise to a general north- 
east dip and carries the horizon of the top of the Pottsville and coal 
No. 2 up to 860 feet above sea level in the southwest corner, whereas its 
altitude in the northeast corner is only 150 feet. The area of greatest 
uplift is flanked on the east by steeply dipping strata and terminated 
on the north by a fault of 100 to 200 feet throw. The dips vary from 
a fraction of a degree to as much as 10^, the steepest dips being found 
along the eastern and northern borders of the hilly country. The 
average slope of the strata is 50 to 75 feet per mile to the northeast. 
The unconsoUdated rocks are approximately horizontal, but are more 
or less confined to certain areas. Some, such as the drift and loess, 
underUe most of the surface; others, such as the alluvium, are local 
and irregular in development. 



Considerable bodies of shale and clay are interbed.ded with the 
heavy resistant sandstone of the Pottsville formation, and no doubt 
most of this material is usable at least for the commoner grades of 
brick, though so far it has not been worked. In general the shale 
and clay are overlain by sandstone, so that they can not be stripped 
profitably. It is possible that some of the beds of clay will be found 
valuable enough to mine. The important clay mined at St. Louis 
and known by the trade name Cheltenham belongs near the top of 
the Pottsville, and it is possible tliat pockets of valuable claywill be 
found at this horizon in the Murphysboro quadrangle. 

Digitized by VjOOQIC 


The coal worked at Murphysboro and known as No. 2 is in a few 
places underlain by plastic clay, but this clay is thin and does not 
appear valuable enough to warrant exploitation. The under clays 
of other post-Pottsville coals seem likewise to be of no great value, 
tliough locally they may be found worth mining. Up to the present 
time no tests have been made on these under clays. 

Apparently the most valuable and accessible shale in the quad- 
rangle is that overlying coal No. 2. This shale is persistent and 
appears to be fairly uniform. It is light gray in color, is fairly firm, 
though it readily becomes soft and plastic on wetting and grinding, 
and contains scattered iron concretions commonly 3 to. 6 inches in 
diameter. As a rule it contains little quartz sand, but mica flakes 
are commonly abundant. The thickness of the shale varies from 
point to point, and this comes about not only through a variation in 
the thickness of individual beds but through a variation in the char- 
acter of the upper part of the member. Thus the shale overlying 
coal No. 2 west of Vergennes is only 20 feet thick and is overlain by a 
soft massive sandstone. South of this point the sandstone grades 
into shale, and near Murphysboro there is an almost unbroken mass 
of shale nearly 100 feet thick, with a thin coal near the top. Ten 
miles to the north this coal is underlain by the heavy sandstone just 
referred to. 

The value of this shale lies principally in the following properties: 
(1) It readily becomes fairly plastic, so that it can be molded by the 
stiff-mud process; (2) it does not shrink greatly on drying and firing; 

(3) there is a considerable range in temperature between the point at 
which it begins to fuse and the point at which it becomes viscous; and 

(4) the burned product has good tensile strength. These characters 
make it a desirable material for paving brick as well as for common 
brick and tile. For paving brick and some other products the shale 
is scarcely as plastic as is desirable, but this can be remedied by the 
addition of the more plastic loess clay, which is present almost every- 
where in this region. Fireproofing requires a very plastic clay, in 
order that it may pass readily through the pecuUarly shaped molds 
which are used. For this purpose it would probably be desirable to 
add 75 per cent or more of surface clay, whereas for paving brick 25 
per cent of surface clay is found sufficient. 

That part of this shale which overUes the thin coal at Murphysboro 
and Ues about 100 feet above coal No. 2 is being worked extensively 
by the Murphysboro Paving Brick Co. at Murphysboro. 

The shale is not valuable enough to warrant underground working 
and therefore its exploitation will be confined to the area in which it 
outcrops or lies under thin cover, so that it can be worked by the 

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common pit or quarry method. The area of its outorop is in the form 
of a strip varying in width from a few feet to 2 miles, extending east 
from Murphysboro to and beyond the boundary of the quandangle and 
north from Murphysboro nearly to the northwest comer of Vergennes 
Township, where it is faulted down to some distance below the surface. 
Most of the outcrop lies near a railroad. 

The group of strata numbered 5 in the generalized section contains 
several fairly continuous beds of shale which are no doubt usable for 
the common clay products, but their oiitcrop is along the easteru and 
northern borders of the quadrangle 2 or 3 miles from railroads and 

The underclay of coal No. 6 is present locally on the eastern and 
northern boundaries of the quadrangle and It may in places be work- 
able at a profit. There are no known workable bodies of this clay 
within the area, though it does not lie far below the surf a^oe. 

The preglacial alluvium is more or lees gravelly, and the parte in 
which clay predominates are deeply buried. The glacial till lies 10 to 
30 feet or more beneath the surface and is made up in large part of fine 
gravel in a clay matrix. Neither of these formations is important as a 
source of clay. 

All the larger streams of the quadrangle once flowed many feet 
below their present position, but their valleys have been partly filled 
with fine sediment so that their old channels now lie buried far below 
the beds where the streamy now flow. The original thickness of the 
filling ranged up to more than 100 feet, but the streams have washed 
away a part of the material and they now flow about midway between 
the former upper surface of the filling and their old buried channels. 
The filling underlies all the low, flat parts of the district, and it is 
extremely irregular in outline. At Murphysboro it is more than 100 
feet thick and consists of yellowish clay containing much fine sand. 
To the east and north the sand gives place to very fine silt, ao fine that 
much of it will pass through filter paper. 

The sandy portion of the valley filling has been worked at several 
small pits, such as that in the northeastern part of Murphysboro, 
where it is overlain by a few feet of loess clay, with which it is mi^^ed. 
It yields a brick of very good grade. The less sandy portion has, so 
far as is known, not been tested and the material is not looked upon 
by practical clay men as very promising for day manufacturing. 
However, it is not unreasonable to suppose that it may be a useful and 
perhaps valuable material to mix with other clays for particular 

Zioeas. — ^Under the term ''loess" is included all the fine yellowish 
material which overlies the glacial till and parts of the valley filling. 

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With the possible exception of the glacial till this is the most wide- 
spread of all the surficial formations, and on account of this wide 
occurrence and its position immediately below the surface it is the 
most accessible. It is fairly uniform in physical and chemical char- 
acters; though it shows a general variation according to its distance 
from the Mississippi. That lying near the xiveit is soft, porous, and 
somewhat calcareous, whereas that 10 to 15 miles from the river is 
compact, impervious, and noncalcareous — ^plastic when wet and hard 
when dry. Ordinary brick has been made successfully from both 
varieties, though it seems desirable to use an admixture of shale 
wherever possible. 

The recent alluvium is not of great importance as a source of clay. 
It is of minor extent, is conmionly gravelly, and is subject to overflow 
several times a year. Along the larger streams, however, there are 
considerable bodies of clay in the ''first bottoms.^' 

mnmoDft or woumro* 

Slude. — ^The only plant at present working shale is that of the 
Murphysboro Paving Brick Co., about 2 miles north of Murphysboro, 
which was opened in January, 1909. The pit is located near a small 
ravine into which surplus water is pumped. The overburden is about 
10 feet of sandy clay, which belongs to the valley fiUing above de- 
scribed. A part of this clay, the lowermost 2 feet, is mixed with the 
shale in the proportion of 25 per cent of clay to 75 per cent of shale, and 
the remainder is discarded. The shale is blasted by dynamite and 
shoveled by hand. The shale and clay are hauled by cable to the 
plant, where they are ground in a dry pan, wetted, molded, and dried 
with waste heat. The bricks are then burned for 12 or 14 days in 
down-draft kilns, coal from a near-by mine being used for fuel. 

CTay.— The valley-filling clay is worked at only a few small pits by 
the ordinary methods of brick manufacture. It would seem, how- 
ever, that ike extensive deposits of clay in the region and the con- 
siderable demand for clay products might warrant more extensive 

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By Alexander Deussek. 


During the winter of 1909-10 the writer collected about 25 samples 
of clays from the central Coastal Plain region of Texas, in connection 
with his work on the stratigraphy and economic geology of this area. 
Tests on the physical properties and burning behavior of these clays 
were made in the laboratory of the Survey at Pittsburg, Pa., under 
the supervision of A. V. Bleininger, ceramic chemist.* A description 
of these deposits and the results of these tests are presented in this 

The area known as the central Coastal Plaiu region of Texas con- 
sists of that portion of the State included between Brazos and San 
Antonio rivers and between the coast and the Missouri, Kansas & 
Texas Railway. Samples were collected from Travis, Lee, Bastrop, 
Burleson, Washington, and Fayette coimties. The location of the 
deposits is shown on the map (PI. VI). 

In geologic age these clays range from Cretaceous to Pleistocene. 
The particular formations represented and sampled were the Eagle 
Ford formation in Travis County, the Taylor marl in Travis County, 
the Cook Mountain formation in Lee and Burleson counties, the 
Jackson formation in Burleson and Fayette counties, the Fleming (?) 
clay in Fayette Coimty, a Miocene clay in Washington County, and 
Pleistocene deposits in Bastrop County. 

The clays include kaolins, brick clays, and fuller's earth. The 
tests on the clays that give promise for use as fuller's earth are now 
in progress at the Bureau of Standards, but the results are not yet 
available for pubUcation. 

In Washington, Lee, Fayette, and Gonzales counties occur a series 
of lenticular, white, kaolin-like clays. These clays have been some- 
what extensively advertised as suitable for the manufacture of pot- 
tery, porcelain, and chinaware, and some excellent samples of china- 
ware have been made from the deposits in Fayette County. The 
results of the tests on these clays have proved more or less disap- 

•The work of testing structural materials was on July 1, 1910, transferred from the United States 
Oeologtoal Survey to the Bureau of Standards, of the Department of Commeiroe and Labor. 


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^ nx, ani^. rT.AYR FROM TEXAS. 


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pointing, and it is extremely doubtful if many of the deposits can be 
used in the manufacture of clay products of the higher grade. How- 
ever, these clays might afford smtable material to mix with other 
clays, so that they might be profitably worked. 

It is undoubtedly true that there are in the area from which these 
days come some deposits of relatively high-grade fuller's earth that 
can be worked at a profit. Attempts at development of two such 
deposits have been made, but both imdertakdngs failed. These 
failures were due in the first place to improper location of plants and 
a lack of knowledge concerning the extent and geology of these 
deposits, and in the second place to the inexperience of the promoters 
in the manufacture of f uUer's earth and the lack of competent business 
organizations capable of marketing the product. It is believed that 
in experienced hands, with plants properly located, these clays can be 
worked at a profit and that they merit additional attention. 


It is desirable to make a few remarks on the methods of interpret- 
ing the results of the tests given in connection with the description 
of the clays. 

The particular properties that give a clay value are those that 
enable it to be molded into any desired form when wet (the property 
of plasticity), to retain this form permanently, and to become hard 
when burned. By burning, a clay loses the property of plasticity. 
These are the two fundamental principles involved in the manufac- 
ture of practically all clay products. 

A good clay should possess the following properties: When ground 
and mixed with water, it should be capable of being molded into any 
desired shape without cracking. Before it can be burned the water 
used in molding must be given a chance to disappear. In other 
words, the green wares must be permitted to dry in the air. A clay 
that does not crack in tUs process of drying is a good drying clay. A 
clay must bum to a good, desirable, and uniform color throughout. 
In addition, it must bum to a condition hard enough to resist abrasion 
with a knife (steel hard) without blistering, swelling, fusing, warping, 
or cracking, retaining the same shape in which it was molded, except, 
perhaps, for a small amount of shrinkage. The most valuable clays 
are those that retain a perfectly white color even after burning to steel- 
hard condition. These are the so-called kaolins. Clays that will not 
fuse and get molten or pasty at the highest temperatures to which 
they may be subjected are known as fire clays. 

The steel-hard condition of clay is attained in the burning when 
some of the more fusible elements of the clay become soft, causing the 

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grains to stick together. This is called incipient fusion. All clay 
products must attain this condition in the process of burning. With a 
further variable increase in temperature, depmiding on the character 
of the clay and ranging from 50"" to 200^ F. or more, most of the 
particles become sufficiently soft to allow them to settle into a com- 
pact, impervious mass, thus closing up all the pores in the clay and 
decidedly reducing the porosity. This condition is termed vitrifi- 
cation. Practically all the particles have been welded into a dense, 
solid mass. Up to this point porosity deca^eases; after this point 
is reached it increases. Only a few day products are carried to this 
temperature or to vitrification, such as vitrified brick, sewer pipe, 
etc. The porous clay products, such as building brick, eaarthenware, 
etc.; are carried only to the point of incipient fusion. If the heat is 
raised beyond the temperature of vitrification, the day softens, no 
longer holds its shape, and flows or gets viscous. This condition is 
called viscosity, or the fusing point. It is needless to remark that thb 
condition must be avoided in the burning of clay products, for if it is 
reached the wares are lost. 

In commercial practice it is not possible to so regulate the heat 
throughout the kiln that it will everywhere show the same tem- 
perature. Different clays vary in the range of temperature between 
the points of incipient fusion and viscosity. That clay is most 
valuable which shows the highest range of temperature between 
these two points. Some limy clays fuse and become worthless at 
60° F. above the temperatiire to which they have to be carried to 
render them sted hard. Some fire clays may be heated 800° F. above 
the point at which they become steel bard before they will fuse. It 
is easily possible to have a difference of temperature of 50° in differ- 
ent parts of any kiln, the result being that with days in which the range 
between the points of incipient fusion and viscosity is at a minimum, 
a considerable number of the brick will reach the fusing point 
and become worthless before the others have reached a temperature 
high enough to make them sted hard. It would not be profitable to 
work days of this character in competition with those that would 
give a larger percentage of perfect brick. For this reason a clay is 
largdy valuable in proportion to the range of temperature between 
these points. 

In the burning of days any sudden change in the porous condition 
of the day (porosity) is always accompanied by sudden shrinkage, 
which may crack the ware and render it Wortbiessi or by swelling, 
which will also render the ware worthless. A clay that bums 6ted 
hard or to a vitrified condition without warping, cracking, dwelling, 
or blistering, retaining the same form in which it was molded, shows 
only a small and regular variation in porosity at the differ^it tem- 
peratures in the burning process. On the other hand, days that pos- 

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sees these defects aad show these faults in burning show ako sudden 
and irregular fluctuations in porosity. The variation and fluctua- 
tion in the porosity of a clay at the different temperatures of the 
burning process therefore form an index to the commercial value oi 
that clay. If the fluctuation is small and regular, the clay is a good 
clay and well adapted for the manufacture of clay products; if the 
fluctuation is extreme, rapid, and irregular, the clay is a poor clay 
and is not adapted for the manufacture of day products. 

Cones are devices to measure the temperature of a kihi at different 
times and in different portions during the burning process. They 
are merely thermometers adapted especially to measuring tem- 
perature under these conditions. Roughly, the cones indicated in 
the statements of tests correspond to the following temparatures: 

Cone .010 1,742^ P., or »50^ C. 

Cone .08 1,814** F., or 990^ C. 

Cone .06 1,886** F., or 1,030^ C. 

Cone .04 1,958** F., or 1,070^ C. 

Cone .02 2,030** F., or 1,110** C. 

Conel 2,102** F., or 1,150** C. 

Cone 3 2,174** F., or 1,190** C. 

Cone 6 2,246** F., or 1,230** C. 

Cone 7 2,318** F., or 1,270** C. 

Cone 9 2,390** F., or 1,310** C. 

"Porosity at cone 7,'* therefore, refers to the porous condition of 
the clay at 2,318° F. A clay having 70 per cent porosity would 
be extremely porous, most of its volume being occupied by air 
space* A clay having 10 per cent porosity would be very compact, 
with the particles close together and very Uttle air space in its volume. 

The tests made on these clays are designed to reproduce identically 
the processes through which a clay would be earned in manufacture. 
In other words, the day is mixed with water, molded, dried in the 
air, and then burned in a kiln, in order to see how it will behave in 
these processes. A diemical analysis can not be depended on to 
afford an idea as to the value of a clay for the manufacture of burned 
products. The only way to arrive at this is by means of such tests 
as are above indicated. 

In the light of these statements it ought to be easy for even a non- 
technical person interested in any particular clay to interpret the 
tests in such a way that he can form a ready notion of its value for 
any purpose. For example, as regards molding behavior, clay No. 
404 (p. 349) is a good clay, because it molds without tearing or showing 
lamination, but clay No. 376 (p. 332) is a poor clay, because it tears 
during the process of molding. As ^regards drying behavior, day 
No. 429 (p. 313) is a good clay, because it does not crack or warp in 
drying, but day No. 393 (p. 339) is a poor day, because it can not 
be dried without cracking and warping. 

94174**— Bull. 470—11 ^20 

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In drying clays shrink. They show additional shrinkage during 
the process of burning. As a rule, clays that show high shrinkage in 
the processes of drying and burning will likewise crack and warp, 
and vice versa. The shrinkage of a clay may therefore be taken as 
an index of its value for the manufacture of day products. The 
shrinkage may be expressed by comparing in terms of percentage 
the relation of the length of the dried brick to that of the wet brick. 
For example, if a brick measures 10 inches in length when wet and 
7.5 inches when dry, the shrinkage is 25 per cent. It will be found 
by an inspection of the tests that a low drying shrinkage is always 
correlated with good drying behavior, and vice versa. For example, 
compare clay No. 403 (p. 321), whose drying shrinkage is 2.7 per cent 
and drying behavior good, with clay No. 382 (p. 337), whose drying 
shrinkage is as high as 12.41 per cent and all pieces of which warped 
and cracked in drying. 

For reasons above explained, a clay should show little variation 
in porosity during the different stages of burning, and if variation 
does occur it should be gradual and not rapid. For example, clay 
No. 405 (p. 324) bums steel hard without cracking, warpiiig, or 
blistering, and its porosity at the different temperatures (cones) 
varies only from 32.60 to 30.30 per cent. On the other hand, in the 
test of clay No. 385 (p. 318), which fused to a glass and lost the form 
in which it had been molded, the porosity dropped very suddenly 
from 48.20 per cent to 0. 

Clays should bum to a red, brown, yellow, cream, buff, or white 
color, and the coloration should be uniform, although a speckled 
color is sometimes desirable. One part should not be cream, another 
red. Clays that fail to meet these color requirements can not be 
considered good clays. Again, unless clays will bum to a steel-hard 
condition, or to the condition of vitrification, practically in the form 
in which they were molded, without cracking, warping, swelling, or 
blistering, they can not be classed as suitable for the manufacture of 
clay products. 

To recapitulate, the criteria which must be applied to a clay to deter- 
mine its value for the manufacture of burned products are the molding 
properties, drying properties, variation in porosity during burning, 
color to which it bums, and hardness after burning. For example, 
compare clay No. 394 (p. 347) with clay No. 382 (p. 337) . No. 394 is a 
valuable clay and could be used in the manufacture of burned prod- 
ucts, because it molds without tearing or laminating, dries without 
cracking, shows a uniform and only gradual variation in porosity 
during burning, and bums to a<air color and to a steel-hard condition. 
No. 382 is, when used without mixing with it other material, worthless 
for the manufacture of bumied products, because it molds unsatisfac- 
torily, showing lamination, warps and cracks in drying, and swells 

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during burning, its variation in porosity is*not uniform nor gradual, 
and its color after burning is unsatisfactory. 

It should be stated that unfavorable properties of one kind and 
another can often be overcome by the addition of some corrective 
material to the clay. Whether this can be done at a profit depends 
on the local conditions, such as the market and the price that can be 
procured for the products, the availability of the materials to be 
added, the ease with which they can be worked, and the cost of labor. 

The following is the report of A. V. Bleininger, who made the burn- 
ing and physical tests on these clays: 

The clays were tested and their behavior noted as regards the following points: 

1. Tempering and amount of water required to produce plasticity. 

2. Working quality, degree of plasticity, and ability to flow through an auger- 
machine die. 

3. Drying characteristics and drying shrinkage. 

4. Behavior in burning as regards progress of vitrification, determination of best 
burning temperature, burning shrinks^, and relation between burning temperature 
and porosity. 

5. Properties of the burnt specimens, color, hardness, and soundness of structure. 
The manipulations carried on in the testing of the clays were as follows: 

The sample was first ground (if dry and hard) in a Stevenson pan, then screened on 
a commercial piano-wire screen, and tempered with the proper amount of water in 
the pan. The plastic mass was put through a Mueller auger machine and shaped into 
a bar 3) by 3} inches, which was cut into briquets 1} inches thick. A certain number 
of these briquets were at once weighed and their volume determined in a Soger volume- 
nometer, petroleum being used as the measiuring liquid. The remainder of the test 
pieces were likewise weighed and then taken into the drying room. Extraordinary 
difficulties were met in drying many of these samples. It was necessary to remake a 
number of the specimens once or twice and to dry them under the most favorable con- 
ditions in a moist atmosphere, keeping them covered with moist cloths for several 
days. Yet, in spite of Hiis precaution and even when the briquets were made by 
hand in brass molds, it was impossible to dry them without their cracking and check- 
ing badly. These tests have been made with so much care that there can be no 
doubt as to the absolute inability of many of these materials to dry satisfactorily under 
commercial conditions. 

So far as possible the volume of the dried specimens was again determined by means 
of the Soger apparatus and the linear shrinkage calculated, thus insuring maximum 

The best burning temperature for each test was determined by cutting 12 small 
briquets, weighing about 100 grams each, out of the larger auger-machine specimens, 
drying, and firing them in a large gas-fired test kiln to the temperatures stated on page 
305. In biiming the specimens the cone temperatures were checked by means of 
the Le Chatelier pyrometer. 

The small briquets, after having been burned, were examined for porosity by obtain- 
ing their dry weight, their weight after immersion in boiling water and in vacuo, and 
their weight when suspended in water. The porosity was then calculated from the 

W— D 
formula P= vy_o XlOO, where P= per cent of porosity, D=dry weight of test piece, 

W=wet weight of test piece, and S«su8pended weight of test piece. 

By plotting the porosities against the temperatures the vitrification range of the 
clays is clearly and definitely determined. It is evident that the more gradual tho 
slope of the curve the longer is the vitrification interval; that is, the safer will the 

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product bum under commerdid conditioiiB. Owing to tiie laige aa» at the kiln the 
rise in temperature was slow, and hence comparable to the condidons of practice. 
Any clay showing abrupt vitrification under these conditions must be condemned 
as unsatisfactory for the production of dense hard building brick or other clay wares. 
The most favomble burning temperature was thus readily determined, and when it 
was possible to obtain whole briquets in drying they were burned to this heat. 




One mile approximately N. 30*^ E. from the Lena spur, about 
15 miles southwest of Lc^ange, on the J. Barton League, and half 
a mile east of the San Antonio & Aranaas Pass Railway, in Fayette 
County, occurs a deposit of whitish talclike clay, which may be classed 
as a kaolin. The location of this deposit is indicated on the accom- 
panying map (PL VI) by No, 434. The property belongs to Henry 
Leitenberg of O^Quinn, Tex. 

This clay is exposed in a small rmvine, where the foHowing section is 

Section in ravine on Leitenberg property. 

1. Soil and gmvel (overbnideii) • 1 

2. Laminated white clay, with kint stzeaks of limooite 2 

3. Hard, dense white "kaolin," breaking with conchoidal fractuze, 

stained and incrusted with limonite on alt joint and fracture 
planes 3 

J. C. Melcher^ of O'Quinn, states that in a boring at this point the 
following beds were passed through below No. 3, of the forgoing 

Section in boring on Leitenberg p t v pertg. 

Pe6L TBOhWi 

4. Bed sandstone 10 

5. Yellowclay 6 

6. White sand 1 

7. PurpUah-blue clay 24 

8. Lignitic clay 1 6 

The '* kaolin" stratum constitutes the commercially valuable clay 
at this point. It occurs in the form of a lai^e lens, covering some 40 
acres and varying in thickness from 3 feet to a reported maximum of 
10 feet.^ 

Borings have been put down on this property in order to ascertain 
the amount of clay available. The results of these borings have been 
furnished by Mr. Melcher and are indicated below. . 

Drill hole No. 91. — ^This boring was made on the south bank of a small branch, 486 
yards east of the railroad and about 50e yards south of the north line of the Leitenbeig 
property. Elevation atsurface, 354 feet. (See PI. VII.) Section shows: 

& The author can not vooch as to ttteoorreotiMM of this figareu NonatonlexpostmoeonnwIiiohraTMli 
abed this thick, and no shafts were open that would pennlt a Teriflotttion of the ststemeiit 

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1. Soil and overburden 1 

2. WMteday (kaolin), ameaaNo. 3of t&e«ectiononpage308 9 

ThiB white clay outcrops along th» bmncb at this point lor a distance of 300 feet. 
DriU hole No. ^.— This kole is located 270 leet S. 46'' £. from hole No. 27. Eleya- 
tion at aiu&ce, 356 feet. The section passed through was as ioUows: 

Section in drill hole No. £8. 

Ft. in. 

1. Soil and overburden 1 

2. Bed and yellow clay 9 

3. Kaolin, same as No. 3 of the section described on page 308. . . 7 6 

4. No record 12 

5. Water-bearing sand, carrying good water; entered 1 

Drill hole No, t9, — ^This hole is located 375 feet east of hole No. 28, on the Leitenberg 
tract of the J. Barton League . The elevation of the suilace is 360 feet. No kaolin was 
found in this hole, indicating that stratum No. 3 of the section described on page 308 
pinches out in the direction of the dip, and that this deposit is lenticular. 

Drill hole No, ^0.— This hole is situated 880 feet S. IS"" W. from hole No. 29. Eleva- 
tion at surface, 358 feet. Section shows: 

Section in driU hole No. SO. 

Ft in. 

1. Soil and overburden 1 1 

2. Kaolin, same as No. 8 of the section described on -page 308. . 9 

Drill hole No. ^1.— This hole is located 600 feet S. 10^ W. from hole No. 30, in a 
ravine where the kaolin outcrops at the surface. This hole revealed the presence of 10 
feet of kaolin at this point. 

Drill hole No. 52.— This hole is situated 330 feet N. 60^ E. from hole No. 31. It was 
begun at the butt end of three mammoth petrified trees. No kaolin was found here. 

The data indicating the amount of material available and the loca- 
tion of these deposits are shown graphically on figure 43 and Plate VII. 

This clay is associated with beds not lower than Jackson nor higher 
than Fleming. It appears to have been deposited in small erosion 
hollows or lakes along the seashore in Jackson or Oligocene time. 
The bed dips slightly to the southeast. The clay is somewhat highly 
jointed and fractured, the average dimensions of the fragments between 
the joint and the fracture planes being 2 by 3 by 4 inches. Within the 
body of the clay each fragment is coated with a film of limonite about 
one-thirtynsecond of an inch thick. When this coat is removed by cut- 
ting with a knif C; however, the remaining clay contains very little iron. 

This deposit is situated in a country that would be classed as poor 
for agriculture. The topography is sublevel, with here and there 
small ravines and ^'washes" along which the clay outcrops. The 
area is veneered with a thin coat of Pleistocene terrace gravels, made 
up of quartZ; flint, jasper, and limestone cobbles. In places the gravel 
is overlain by 6 inches to 1 foot of gray to brown clay loam soil ref- 
erable to the Lufkin soil series as recognized by the Bureau of Soils, 
and the region is generally covered with a fairly thick growth of 
post-oak timber. 

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The overburden, as indicated by the borings described above, 
ranges in thickness from 1 foot to 10 feet and will easily average 4 feet 
over the entire area of 40 acres. This material consists of gray clay 
soil, 3 to 12 inches of gravel, and in places 2 to 9 feet of white, red, 
or yellow clay. It is very doubtful if any of this material could be 
utilized for any purpose, and the removal of 4 feet of overburden 
would have to appear as a charge of at least 20 cents a ton against the 
kaolin quarried. 

Piguhe 43.— Map of the ylcinity of Lena, Fayette County, Tex., showing location of bore holes put down to 
detennine extent of kaolin on Ldtenbeng property, "a " preceded by number Indicates elevation of top 
of kaoUn; **b" elevation of bottom of kaolin. Contours are subject to ooneotion. 

On the assumption of an average of 5 feet of kaolin over an area of 
40 acres and a specific gravity of 2.5, about 600,000 tons of kaolin is 
available in this deposit. 

Among the kaolin prospects of Texas this particular deposit is per- 
haps most favorably situated with respect to transportation facilities. 
It is located practically adjacent to the Waco division of the San 
Antonio & Aransas Pass Railway, and half a mile of spur track would 
reach the entire deposit. It is but 158.4 miles distant by rail to the 
seaboard at Galveston, the freight charges to that city being $1.10 
a ton. The freight charges to Trenton, N. J., are about $5«90 a ton. 


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Abundant fuel is available in the form of lignite and wood. lig- 
nite mines are operated at Rockdale, in Milam County , 60.4 miles dis- 
tant on the same railroad, and at Phelan, in the adjoining county of 
Bastrop, 36 miles distant by rail. A deposit of lignite occurs only 1 or 
2 miles north of the clay, but is not worked at the present time. (See 
PI. yil.) This deposit is capable of being worked at a profit and 
doubtless wiU be mined in the not distant future. Lignite can be laid 
down at the Leitenberg clay deposit at prices closely approximating 
$1.15 a ton. Good post-oak wood can be delivered at prices ranging 
from $3 to $3.50 a cord. 

Water satisfactory for steaming and domestic use and in inex- 
haustible quantity can be had in wells ranging in depth from 100 to 
400 feet. 

The item of labor will present some difficulty. Negro and Mexican 
labor will have to be employed, and at best this labor will not be very 
satisfactory for the peculiar work that this clay will require in prepa- 
ration. Such labor can be had at prices ranging from $1 to $1.50 a 

Clay pits opened at this point will be readily susceptible to drain- 
Age by open ditches leading into ravines emptying into Buckner 

This deposit was worked for a brief period in 1908 by the Texas 
Kaolin Co., whose office was situated at Chicago, 111. A number of 
small pits were opened and six carloads of the prepared clay were 
shipped to the potters in New Jersey. Operations were soon sus- 
pended, however, and no work has been imdertaken since. The clay 
was dug out with a pick and shovel, the coating of limouite or iron 
stain was cut oflf by hand with a jackknife, and the clay was then 
crushed to pea size with a hammer, sacked, and shipped. A consid- 
erable body of the clay which had been crushed and from which the 
iron had been removed in the manner above indicated was spread out 
in a small yard to weather. Some of the material that had been 
weathered for about a year and a half in this way was sampled and 
tested to determine its value for the manufacture of clay products. 
The results of these tests appear below. 

Bttming bdumior and pkytieal properHea of kaolin on Leitenberg property near Lena, 
FayetU County {No. 4S4B), 

Deecription of raw clay Peculiar structure. Amorphous lump siur- 

rounded by white bonding material. 
White, soft. 

Molding behavior Grood plasticity* Works well in machine. 

Drying behavior Cracks very badly. 

Drying shrinkage: 

Per cent of wet length 8. 38 

Per cent of wet volume 32. 8 

Burning shrinkage, per cent of wet length . 6. 9 

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Total linear ahrinkage, per cent of wet 

length 16.26 

Poroaity at cone 010 per cent. . 16. 4 

.08 do.... 7.6 

.06 do 6.7 

.04 do.... 9.3 

.02 do.... 10.2 

1 do.... 8.2 

3 do.... 14.2 

5 do.... 9.5 

7 do.... 10.6 

9 do.... 11.1 

Color after burning (rood wbite. 

Hardness Steel hard . 

Remarks A good color holds throughout. Evidence 

of vitrification at cone 9. The only 
clay in the series which is promising ae 
a kaolin. 

From these tests it appears that this clay, if mixed with a small 
amount of corrective material to prevent cracking in drying, would 
be suitable for the manufacture of white earthenware, chinaware^ 
etc. J. C. Melcher has had some flawless samples of chinaware 
burned from this clay with an admixture of 75 per cent foreign clay. 

It is stated that the clay was prepared ready for shipment as indi- 
cated above by negroes and Mexicans at a cost of $3 a ton, which 
included the cost of quarrying, removing the iron, crushing, and 
sacking. The cost of delivering to the railroad was stated to be 
35 cents a ton. The writer has no accurate cost data covering these 
points, but if these figures are correct, the cost of delivering a ton 
of this clay to the potters at Trenton, N. J., would be $12 a ton, 
figuring royalty at $1, freight at $5.90, quarrying, mining, and 
preparing at $3, hauling at 35 cents, bags at $1, depreciation at 25 
cents, and management at 50 cents. This should allow adequate 
profits on the mining and shipping of this clay. 

It appears that operations were suspended at this point because 
the potters found that the clay was not adapted to their needs — in 
what particular way is not apparent. The results of the tests here 
reported seem to indicate that the only objection that might be 
offered to this clay is the difficulty experienced in drying it without 
cracking. The color is good, the clay bums to steel-hard condition 
without cracking, warping, or blistering, and its fluctuation in po- 
rosity is not viol^Qit nor extreme. It is hardly probable that the 
clay was rejected by the potters on accoimt of its poor drying quaU- 
ties alone, as this defect could be corrected by the addition of quartz 
sand. It is probable that difficulty was experienced in the burning 
of the wares and that the colors and hardness proved unsatisfactory. 
In view of the fact that the results given in this paper were obtained 

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on clay that had been weathered for a year and a half, it may be 
that anoth^ trial by the potteis on weathered material would give 
more satisfactory results. 

In order to determine if any use could be made of some of the 
overburden (clay No. 434A) on this kaolin, stratum No. 2 of the sec- 
tion described on page 308 was sampled and its physical properties 
and burning behavior tested. The results appear below. 

Burning behavior and phymcal properH«$ of white clay on Leiienberg kmd near Lena 

(No. 434A). 

DeBcription of raw clay White, solt lamioated clay. QrindB up 


Molding behavior Plasticity fair. Good column. No visible 


Drying behavior Dr3dng behavior fair. Some cracking on 

air drjdng. 

Dryiiig shrinkage, per cent of wet volume. 2& 64 

Porosity at cone . 010 percent.. 23.90 

.08 do.... 11.20 

.06 do.... 

.04, .02,1 Glassy Btiructoie. 

Color aftnr bumiiig Pink at the lower tem]>erature, but hdM 

to a buff at the higher temperature. 

Hardness Soft at cone .08. Vitrified at cone .06. 

Best burning temperature 1,020^ C. 

Remarks Temperature range very short. Not suit- 
able for commercial use. 

The results of these tests seem to indicate that this material by 
itself could not be used in the manufacture of clay products, but it 
may possibly be used as a corrective to be added to other clays that 
may be burned in this vicinity. In quarrying operations, it would 
be advisable to keep this material at least separate from the gravel 
and soil and from other clays that form a part of the overburden. 


Near the northwest comer of the W. F. Hamilton League, about 3 
miles southwest of Plum, Fayette Coimty, at a definite geologic 
horizon, is found a series of isolated small lenses of massive, soft white 
siliceous clay that is locally called '* pumice dust." The location is 
more definitely indicated on the accompanying map (PL VTI, point 
No. 63). The land on which the clay occurs belongs to J. C. Melcher, 
of O'Quinn, but leases on it are owned by the Foerster & Baer Co., 
128 Wisconsin Street, Milwaukee, Wis. 

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At the point marked No. 62 on Plate VII, at the north line of the 
W. F. Hamilton League, the following section is exposed: 

Section at north line of W. F. Ilamilton League, 

Pleistocene: Feat. 

1. Gravel, consisting of cobbles and pebbles of flint, quartz, 

jasper, etc.; smtable for railroad ballast 2 

Fleming clay: 

2. White siliceous clay, so-called "pumice dust " 3 

3. Brown shale or fuller's earth (7) 10 

The lateral extent of the clay lens (No. 2 of the section) at this 
particular point does not appear to be very great, not exceeding 300 
feet along the strike line. 

Similar lenses are exposed at the same horizon at the points marked 
58, 59, 60, 61, 63, 64, and 65 on Plate VII, the area in which these 
lenses outcrop having an average diameter of about three-fourths of 
a mile. At the point marked 65 a lens 20 inches thick outcrops; at 
the point marked 64 a lens 2 feet thick outcrops; at the point marked 
60 a lens 2 feet 6 inches thick outcrops. Similar lenses also outcrop 
in Fayette County several miles to the northeast of this locality. 

The country here is generally sublevel, dissected in places by ravines 
and gullies, wliich would readily permit clay pits to be drained with- 
out the aid of pimips. The area is somewhat completely mantled 
with a deposit of gravel, as described above, that ranges from 6 
inches to 2 feet in thickness. Should the deposit be tapped by a 
railroad spur, this gravel could be marketed as railroad ballast at a 
price that would at least pay for the cost of its removal. 

This deposit is located some 2 miles from the Waco division of the 
San Antonio & Aransas Pass Railway, and about 3^ miles from the 
main line of the Missouri, Kansas & Texas Railway. It is doubtful, 
however, whether the quantity or the value of the material available 
here would justify the building of a spiu- to this point. 

The conditions as regards fuel, water, and labor for this deposit 
are identical with those indicated for the kaolin on the Leitenberg 
property, to the southeast. This siliceous clay is at very nearly the 
same geologic horizon as the kaolin on the Leitenberg property, though 
it may occupy a sUghtly higher stratigraphic position. It appears to 
have been formed essentially under the same conditions as the kaolin. 

This deposit has been worked to a slight extent. Leases have 
been secured on it by Foerster & Baer, of Milwaukee, Wis., and some 
26 tons of material has been shipped. The clay was merely dug out 
with pick and shovel at one of the outcrops and hauled by wagon to 
the shipping point 2 miles distant. It is not being mined at the 
present time. 

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The following are the results of the tests made on this clay to 
determine its value for the manufacture of day products: 

Burning behavior and physical properties of* 'pumice dust" near Plum, Fayette County 

(No. 4t9), 

Description of raw clay White siliceous clay, soft, massive. Grinds 

up easily in dry pan. 

Molding behavior Plasticity low. Necessary to mold dry 

pressed. \ery sandy. 

Drying behavior Good drying qualities. 

Drying shrinkage: 

Per cent of wet length 0. 5 

Per cent of wet volume 5 

Porosity at cone . 010 per cent. . 50. 5 

.08 do.... 42.9 

.06 do 43.4 

.04 do.... 21.70 

.02 do 7.0 

1 do 05 

3 do 

5 do 

Color after burning Yellowish. 

Hardness Vitrifies steel hard. 

Best burning temperature 1,070** C. 

Remarks Its poor working qualities and short tem- 
perature range do not allow its use in 
commercial work. 

Ries* reports the following as the chemical composition of this 

Analysis of '* pumice dust " fiom point near Lena, Fayette County, 

Silica (SiO,) 72.61 

Alumina (AlaO,) 15. 00 

Ferric oxide (FejO,) 81 

Lime(CaO) 60 

Magnesia (MgO) 33 

SodaCNajO) 33 

Potash (K,0) Tr. 

Titanic acid (TiOa) 52 

Hydrous silica 13. 73 

Water. 8.31 

Total fluxes 2.07 

The results of the tests of this material indicate that it is not 
adapted to the manufacture of any burned products. This is in 
substantial accord with results obtained by other clay experts and 
by a number of potters. The material may possibly be used as a 
corrective to be added to other clays, as an abrasive material, or in 
the manufacture of white Portland cement. 

1 Biet, Helnrtobf Th« dayi of Tuns: Boll. Univ. Texas No. 102^ 1908, p. 277. 

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About 4 miles noiHiwest of Burton, in Washington County, on 
the S. O. Tatuju farm, in the same geologic foimation and appar- 
ently at the same horizon as the kaolin on the Leitenberg property, 
occurs another deposit of white talclike clay, that is locally called a 
'^ kaolin/' The location of this deposit is shown on Plate VI (point 
marked 390). The deposit belongs to S. O. Tatum, of Burton* 

This clay occurs here as a lens in highly cross^bedded gray sands. 
At this particular point the lens is 75 feet in diameter along the 
line exposed to view, and at its thickest point it is 10 feet in vertical 
extent, but it thins out rapidly on either side. There are probably 
several of these lenses present at this locality. It is probable that 
in order to win this clay in the most economical manner the material 
would have to be mined out. 

The clay on freshly broken surfaces has a greenish tint, but when 
dried out it is perfectly white. No iron stains are visible on the 
joint and fracture planes. The clay is extensively seamed in all 
directions, the distance between the seams avere^ing 2 feet. Along 
these seams or joint planes no iron discoloration appears. 

At the point of exposure the average thickness of the overlying 
gray sandstones is 3 feet. The material underneath, the white clay 
is a loose porous bluish sand, and there is an erosion unconformity 
between the overlying white clay and gray sandstones and the 
underlying bluish sand. Apparently this clay, like the others of 
similar character, was deposited in an erosion hollow during Oligo- 
cene-Miocene time. 

The deposit is not very extensive at this point, and it is somewhat 
doubtful whether there is a quantity sufficient to warrant opera- 
tions even if the clay were of suitable quality. This is a matter, 
however, that will have to be determined by careful prospecting. 

The accompanying sketch map (PI. VIII) indicates the general 
geography in this vicinity and shows the location of certain drill 
holes and shafts put down to determine the extent of this deposit. 
In. none of these holes was any kaolin struck except in No. 4. The 
record of this boring, as given by Frank Graves, of Burton, indi- 
cates that there is present here 27 feet of brown clay or fuller's earth 
At a depth of 61 feet ** kaolin" was met. The clay was not drilled 
into here because, it is stated, water was encountered. 

The country in the immediate vicinity of the outcrop is much 
dissected into a kind of badland topography. Drainage of open pits 
could doubtless be easily accomplished. In the interstream areas 
the countiy is a sublevel treeless prairie, with a soil of the Houston 
black clay type. As previously indicated, if a demand should ever 
develop for lliis clay it could probably be most profitably won by 
mining, though the matter of roof would present some difficulty. 

Digitized by 




M ft of stripping 
9 ff.of fullers earth 

Area underloin B 
with kaolin ei 


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This deposit lies 2 miles distant from the Austin branch of the 
Houston & Texas Central Railroad. A q>ur could be easily con* 
structed. For fuel, lignite from the mines at Ledbetter, 7 miles 
distant by rail, can be had at prices not exceeding $1.25 a ton. 
Cordwood and wood for timbering is available in the immediate 
vicinity. Water suitable for steaming and domestic purposes can 
be had in abundant quantity in wells not exceeding 300 feet in depth 
or from a large perpetual spring within a few yards of the point of 
outcrop. The labor situation is similar to that indicated for other 

The deposit has not yet been worked, and it is doubtful if its 
quality is such as to cause any demand for this clay at the present 
time. The following are the results of burning and other tests 
made on this day: 

Burning behavior andphydcal properties of kaolin on Tatwn/arm near Burton {No, S90), 

Description of raw day Maamve, fine-grained, tough white clay. 

GfiadB with difScuhy. 
Molding behavior Flafiticity good. Works nieely in ma- 
chine. No lamination. 

Drying behavior Drying behavior good. 

Drying ahrinkage: 

Per cent of wet length 6.9 

Per cent of wet volume 21. 78 

Burning shrinkage, per cent of wet length . 17. 70 
Total linear shrinkage, per cent of wet 

length 24.60 

PoroflityatGone.OlO percent.. 32.60 

.08 do.... 20.60 

.06 do...: .95 

.04 do.... 1.09 

.02 do.... 1.6 

1 do 5 

3 do 57 

5 do.... 3.20 

7 do.... 5.70 

Color after burning Buff. 

Hardness Soft at cone .010. Vitreous at cone .06. 

Best burning temperature 1,020** C. 

Remarks Short temperature range . Above 1 , 150** C . 

the fltnictusv becomes veacular and at 
1,300'' G. the clay is badly swollen. 

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The following is an analysis of this clay, made by T. B. Tucker, an 
advanced chemistry student in the University of Texas: 

Analysis of clay from Tatumfarm^ near Bttrton. 

Silica (SiO,) 67.18 

Alumina (AlaO,) 13.96 

Ferric oxide (FcjOj) L 25 

Lime (CaO) 1. 94 

Magnesia (MgO) L36 

Soda (NaaO) 2. 77 

Potaah(KaO) L43 

Loss on ignition , 10. 06 

Total fluxing impurities 8. 75 

It is apparent from the above analysis that this clay can not be 
classed as a true kaolin, and it would not by itself be adapted to the 
manufacture of any kind of pottery or white earthenware. 


On the Brown place, 4 miles southwest of Somerville and 1 mile 
north of the Yegua Creek crossing of the Burton-Somerville road, in 
the southern comer of Burleson County, occurs another deposit of 
whitish talcUke clay, similar to those previously described. This 
deposit apparently occurs at a geologic horizon sUghtly lower than 
that of the deposits thus far described — ^in the upper part of the 
Jackson formation, immediately beneath the hard sandstones of the 
Catahoula formation and not above them Uke the kaolin on the 
Leitenberg property. It is apparently of the same mode of origin, 
having been deposited in erosion hollows developed during the erosion 
interval of post^Eocene and pre-Oligocene time. 

The country in this vicinity is somewhat hilly and is covered with a 
veneer of quartz, flint, jasper, and limestone gravel (Pleistocene) aver- 
aging 6 inches in thickness. Beneath this occurs some 2 feet of black- 
clay soil, beneath which in turn is found the so-called kaolin. The 
thickness of the clay at this point is not determined, but is believed to 
be not less than 3 feet. 

M. M. Graves, of Somerville, states that he has traced this stratum 
for a distance of three-fourths of a mile by means of borings. The 
records of these borings are unfortimately not available, and the 
writer is unable to give positive information on the extent of this 

This deposit is 4 miles distant from the nearest railroad — the main 
line of the Gulf, Colorado & Santa Fe Railway at Somerville. For 
fuel, lignite from the mines at Milano and Rockdale, 33 and 43 miles 
distant, respectively, by rail, can be laid down at Somerville at prices 
not exceeding SI. 25 a ton. Cordwood can be had here at prices 

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ranging from $2 to $3 a cord delivered. Negro and Mexican labor is 
available at prices ranging from $1 to $1.50 a day. Water siu table 
for generating steam can be obtained in wells ranging in depth from 
300 to 600 feet. 

Below are given the results of burning and other tests made on this 

Burning behavior and physical properties of ''kaolin" on Brovm place, 4 miles southwest 

of Somervilh ( No . S85) . 

DeecripUon of raw clay Massive, white, medium fine-grained clay. 

Grinds easily. Has a detritus of hard 
angular pebbles. 
Molding behavior Plasticity low. Not workable' by stiff- 
mud process. Molded dry press. 

Drying behavior Drying behavior good. 

Drying shrinkage, per cent of wet volume. . 1. 12 

Porosity at cone . 010 per cent. . 48. 20 

.08 .' 34.60 

.06 do.... 28.30 

.04 do 

• 02, 1, 3 Glassy structure. 

Color after burning Buff at lower temperature. Brown where 


Hardness Softat cones .010, .08, .06. Vitrified at cone 

.04 and above. 

Best burning temperature 1,030** C. 

Remarks Temperature range -very short. Not suit- 
able for commercial work. 

It appears from the tests made that this material is not classifiable 
as a kaolin, owing to the comparatively low temperature at which it 
fuses, and it is doubtful if this clay has any commercial value for the 
manufacture of clay products. 



On the Williams place, 2 miles southeast of Somerville, in Wash- 
ington Coimty, occurs another deposit of so-K^alled kaolin, similar in 
character, origin, and geologic relations to the *' kaolins" on the 
Brown and Tatum properties. Just at this point is situated the 
northward-facing escarpment formed by the Catahoula formation, 
which determines the course of Yegua Creek, flowing at its foot. 
This escarpment rises some 100 feet above the level of the adjacent 
plain. Immediately underneath the gray sandstones, which form 
the cap rock of the hills and are, so far as could be determined, about 
15 feet thick, occurs a lenticular body of white talcUke clay, varying 
in thickness from 5 to 20 feet. The distance that this deposit 
extends to the south, in the direction of the dip, is not known, no bor- 
ings having been put down on it. Along the face of the bluff the 
outcrop can be txaoed for a distance of at least one-fourth of a 

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The geologic relations of this deposit are very mnilar to these of 
the ''kaolin" on the Brown property. The depoait occurs in the 
uppermost portion of the Jackson fonnation, b^ng apparontiy un- 
conformable with the formations above and below. Here also the 
hard sandstones of the Catahoula formation rest directly on top of 
the clay. Apparently this deposit, like the ''kaolin" on the Brown 
property, was deposited in erosion hollows developed on the land 
surface of post-Eocene and pre-Oligocene time. 

No openings of any kind have thus far been made into this deposit, 
and no borings have been undertaken to prove its extent. It has 
therefore not been possible to get a good view of the physical char- 
acter of the deposit. The fragments detached from the outcrop were 
generally greenish white in color, but dried out to perfectly white 
masses. No considerable iron discoloration along joint and fracture 
planes was apparent. 

This deposit hes one-fourth mile east of the main Une of the Gulf, 
Colorado & Santa Fe Railway and could be readily reached by a 
spur. It could in all probability be most economically worked by 
mining, a good roof being present and timber being available for 
this purpose. The conditions as regards fuel, labor, and water for 
this deposit are identical with those indicated for the "kaolin" on 
the Brown property. 

Below are given the results of the tests made on this clay: 

Burning behavior and physical properties of ** kaolin" on the WUliams property y t mile» 
ioutheaU ofSomeruille (JVo. S84). 

Deecription of raw clay White) fine-drained, mafieive day, with 

yellow diBcolocationa. Grinda easiiy. 

Molding behavior Plasticity low. Could not be wozked by 

stiff-mud process. Made up dry press. 

Drying behavior Good 

Porosity at cone . 010 per cent. . 61. 40 

.08 do.... 46.70 

.06 do.... 46.60 

.04 do.... 29.1 

.02 do.... 20.9 

1 do.... 22.0 

3 do.... 16.5 ' 

5 do.... 9.7 

7 do.... 2.7 

9 do.... 

Color after burning Buff at lower temperatures, changing to 


Hardness Soft at cones .010, .08, and .06. Steel hard 

at cone 5. 

Best burning temperature 1,230° C. 

Remarks The poor working properties and unsatis- 
factory color make this clay somewhat 
undesirable. It has a good temperature 
range and may be used in the manutec- 
ture of dry-pressed bricks. 

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It may be that if the iron were removed in a manner similar to 
that indicated for the clay on the Leitenberg property this clay 
might find use in the manufacture of clay products of the higher 
grades. The ease and facility with which it can be worked, the 
favorable location, and the facilities as regards transportation, 
market; quarrying, and fuel make it a deposit that merits careful 
attention. It is possible to quarry and market the overlying rock 
at a profit in addition to the clay underneath, and- the elevated 
position of these two deposits would make operations of this kind 
very economical. Natural drainage can be depended on to relieve 
the pits and quarries of water. 


On the Thomas W. Ward League, 7} miles north of Burton, the 
nearest railroad station, in Lee County, occurs another lenticular 
mass of white talclike clays, similar to those previously described. 
The writer has very little first-hand information on this deposit, but 
the following data have been furnished by M. M. Graves, of Somerville : 

The deposit is said to average 10 feet in thickness and to cover 
some 30 or 40 acres of ground. It is covered with an overburden of 
soil and gravel that averages 2 feet in thickness. Iron stains or 
films of limonite appear on the joint and fracture planes. 

The available fuel is lignite from the mines at Ledbetter and wood 
from the immediate vicinity of the deposit. Water can be had in 
wells not exceeding 500 feet in depth. 

The burning tests made on this clay do not indicate that it is of 
great commercial value, and it is doubtful if it would have any use 
in the manufacture of clay products. The following are the results 
of these tests: 

Burning behavior and phyncal properties of *^ kaolin*^ on Johnson placSy 7^ miles north 

of Burton (No. 40S). 

Description of raw clay Soft, white laminated clay ; yellow dis- 

coloratioDB along planes of lamination. 
Grinds easily. 

Molding behavior Plasticity low. Clay very short. Did not 

work well through machine. 

Drying behavior Good. 

Drying shrinkage: 

Per cent of wet length 2.7 

Per cent of wet volume 6. 86 

Burning shrinkage, per cent of dry length . 0. 9 
Total linear shrinkage, per cent of wet 

length 3.6 

Porosity at cone .010 per cent. . 45. 1 

.08 do... 29.50 

.06 do... 17.9 

.04 do... 

94174**— Bull. 470—11 ^21 

Digitized by VjOOQIC 


Color after burning Bufif at lower temperaturee, changing to 

salmon at higher. 
Hardness Soft at cones .010, .08, .06. Steel hard at 

cone .04. 

Best burning temperature 1,050® C. 

Remarks Very short temperature range and poor 

working qualities render the clay unfit for 



On the farm of B. F. Elliott on Kerr Creek, and on the J. B. Fiyor 
League in Washington County, occurs a considerable body of green 
shale that is valuable for the manufacture of building brick. The 
deposit belongs to B. F. Elliott, of Burton. The location is about 
1 mile north of the point marked No. 390 on Plate VI (p. 302). 

This deposit is of palustrine origin, having been deposited in a 
swamp or lagoon adjacent to the shore, apparently in Jackson time. 

The deposit is very well exposed in the canyon walls of Kerr Creek 
on the J. B. Fryor League, where the following section may be seen: 

Section in canyon of Kerr Creek. 

Ft. In. 

1. Brown clay loam soil and subsoil 6 

2. Laminated gray sandstone (would form good roof in case this 

clay was mined) 10 

3. Green shale (said to be 11 feet in thickness), exposed 3 

13 6 

The deposit under discussion (No. 3 of the section) is a hard, fine- 
grained, massive green shale with a pearly luster when wet. The 
dip of the beds here is slightly to the south. 

This shale outcrops along the creek for a distance of 400 yards. 
It is stated by Frank Graves, of Burton, that this deposit covers 
some 120 acres of ground. At the point of exposure the overburden 
is too thick to be removed at a profit, and doubtless the clay could 
be won more economically by mining than by stripping, but there is 
some doubt as to whether the value of this clay is such as to justify 
mining operations. It is probable, however, that by following this 
clay up the dip it can be found without more than 6 feet of over- 
burden, in a situation where the clay could be handled as easily as at 
the outcrop mentioned. 

The topography in this vicinity varies from sublevel to hilly. The 
soil is a poor gray sandy soil of the Lufkin and Norfolk soil series, 
and the country is in places covered extensively with post oak. The 
deposit is 3 miles distant from the Austin branch of the Houston & 
Texas Central Railroad and could be readily reached with a spur. 

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The conditions as regards fuel, labor, and water are similar to those 
indicated for the other clay deposits in the general vicinity of Burton. 
This clay may possibly possess value for fuller's earth, though no 
tests to determine this point have been made. Tests made to deter- 
mine its burning behavior indicate that this clay may be successfully 
utilized for the manufacture of building brick. The clay possesses 
good vitrifying quaUties. The following are the results of the tests: 

Burning behavior and phyiioal properties of day on B, F, UUioU farm^ near Burton 

(No. 340). 

Description of raw clay Hard, fine-grained green shale. Somewhat 

conchoidal fracture. Grinds easily; no 

Molding behavior Plasticity good. Gives fine smooth column 

on the machine. No visible lamination. 

Drying behavior Gives trouble in drying. Pieces used in 

volume meaflurements cracked. 
Drying shrinkage : 

Per cent of wet length 11. 95 

Per cent of wet volume 35. 28 

Burning shrinkage, per cent of wet length . 10. 40 
Total linear shrinkage, per cent of wet 

length 2L35 

Porosity at cone .010 per cent. 23. 70 

.08 do... 18.40 

.06 do. . . 8. 9 

.04 do... 8.9 

.02 do... 8.9 

1 do... 7.8 

3 do... 8.2 

7, 9 Melting point not determined. Draw trials 


Color after burning Buff at cones .010, .08, .06; changes to 

red at higher temperature. 

Hardness Steel hard above cone .06. 

Best burning temperature 1,150® C. 

Remarks This clay has a good vitrification and is a 

promising material for building brick. 

Mr. Frank Graves has furnished the following, which is said to be 
an analysis of this clay made by W. W. Camp, of Denver, Colo. : 

Analysis of clay on B. F. Elliott famij near Burton. 

Silica (SiOa) 61. 56 

Alumina (AlaO,) 19. 25 

Iron oxide (FejOa) 1. 65 

Magnesia (MgO) 79 

Lime (CaO) 1. 10 

Alkalies 1.86 

Water 13.79 


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If this analysis is tnistworthy, it indicates that this clay would 
also be valuable for use in Portland cement if there were any limestone 
in this vicinity that would be suited for this purpose. Unfortunately 
there is no such limestone near by, but the clay may possibly be uti- 
lized in connection with some of the Portland cement limestones that 
occur 40 or 50 miles to the west of this deposit. 


At Lexington, Lee County, a mottled-red, sandy surface clay is 
manufactured into building brick by the Lexington Brick & Tile Co. 
The location of this deposit is marked No. 405 on the accompanying 
map (PL VI, p. 302). 

This deposit is the weathered surface clay which represents the 
altered form of a sandy-clay member of the Cook Mountain forma- 
tion of the Eocene Claiborne group. The original clay is doubtless 
of palustrine origin, having been deposited in a swamp near or close 
to the shore in Cook Mountain time. 

In the clay pit at this point there is 5 feet of this mottled-red 
sandy surface clay. Small concretions of iron and lime about one- 
fourth inch in diameter are fairly well distributed throughout the 
mass of the clay. Only the surface clay is worked, the underlying 
clay not being utilized. The deposit covers 5 acres. The over- 
burden consists of a loose sandy soil, 1 foot thick, and is removed 
by scraping. 

The pit is drained by siphoning the water into the adjacent creek, 
the bed of which lies at a lower level than the bottom of the pit. 
The pit and plant are beside the Waco division of the San Antonio & 
Aransas Pass Railway, the only railroad outlet for this clay. The 
land here is covered with post-oak timber, which has to be removed 
in working the clay, but value of the wood pays for the cost of its 

Brick has been manufactured here only since the early part of 
1910. The clay bums into a red brick, slightly spotted. A system 
of air-drying only is used. The stiff-mud process of manufacture 
is employed. The clay is taken from the pit by plows and scrapers 
and is permitted to weather in the yard for a month or more. After 
weathering the clay is fed to a pug mill, where it is thoroughly ground 
and mixed with water, and then it goes to the stiff-mud machine and 
is pressed into green bricks. The capacity of the machine is 20,000 
bricks a day. One ^'scove kiln" is used for firing. For fuel in the 
kiln wood is used, which is deUvered at the yard at $2.25 a cord. 
For fuel in the power plant to drive the mixing machinery, etc., 
lignite is used, being delivered from the Rockdale mines at a cost of 
$1.13 a ton. White and negro men are employed at $1.25 a day. 
The bricks as loaded on the cars command a price ranging from $8 
to $10 a thousand. 

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This clay is well adapted for the manufacture of building brick. 
It bums to a good red color, and the temperatures at which the clay 
becomes steel hard and viscous are well separated, so that there is no 
danger of overbuming some of the brick while the others have not 
yet attained a steel-hard condition. On the other hand, the clay 
cracks while drying in air, an undesirable property, and must be 
dried carefully and slowly in order to avoid this difficulty. The 
following are the results of the tests in detail: 

Burning behavior and physical properties of the clay of the Lexington Brick dc Tile Co. at 

Lexington (No. 405). 

Description of raw clay Mottled-red, sandy surface clay, soft. Tem- 
pered in wet pan. 

Molding behavior Very plastic and sticky. Contains fine 

sand. Works well in machine. 

Drying behavior Cracks drying in air. 

Dr3ring shrinkage: 

Per cent of wet length 6. 7 

Per cent of wet volume 20. 60 

Burning shrinkage, per cent of wet length . 0. 53 
Total linear shrinkage, per cent of wet 

length 7.23 

Porosity at cone . 010 per cent. . 31. 8 

.08 do.... 32.60 

.06 do.... 31.20 

.04 do.... 31.60 

.02 do.... 32.40 

1 do.... 31.60 

3 do.... 32.30 

5 do.... 30.60 

7 do 30.30 

9 Fuses cone 13. 

Color after burning Good red. Best clay in series. 

Hardness Steel hard. 

Best burning temperature 1,090M,210'* C. 

Remarks The best red burning clay in the series in 

regard to color. Requires careful dry- 
ing. Has a long vitrification range. 


On the land of William Bauer (post office Burton), 125 yards north 
of the depot at Burton, in Washington County, occurs a considerable 
body of calcareous clay. The location is shown by No. 392 on Plate VI 
(p. 302). This clay occurs close to the base of the Miocene beds in this 
portion of the State. It is apparently of Uttoral origin, having been 
deposited in shallow water adjacent to the shore in Miocene time. 

This clay is well exposed in the bank of the creek that flows behind 
the Bauer gin at Burton. This bank shows a deposit of 20 feet of 
gray, calcareous clay. It is overlain by 2 feet of black clay soil, 
which would have to be removed in working. This deposit covers 

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25 or 30 acres of ground, and over this area at least 20 feet of clay is 

The country consists of rolling, treeless prairie. Drainage can 
be secured by a gravity system. Transportation facilities are good, 
the clay being located alongside the Austin, branch of the Houston & 
Texas Central Railroad. For water, impounding reservoirs would 
most probably have to be constructed, as the well water, which may 
be obtained here at a depth of 50 feet below the surface, scales the 
boilers badly. The conditions as regards labor and fuel for this 
deposit are identical with those for other clay deposits in the vicinity 
of Burton. 

Burning tests made on this clay indicate that it bums to a good buff 
color and is suitable for the manufacture of soft building brick. On 
the other hand, it gives difficulty in drying and would have to be 
carefully handled. The following are the results of the tests in 

Burning behavior and phyaioal properties of the day on the land of William Bauer at 

BurUm (No. S9i). 

Description of raw clay Gray calcareous clay; grinds easily. 

Molding behavior Good working plasticity; somewhat sandy. 

Drying behavior Volume pieces made in a mold by hand. 

Warped and cracked in drying. 
'Drying shrinkage, per cent of wet length . . 7. 56 

Porosity at cone . 010 percent.. 31.0 

.08 do.... 41.1 

.06 do.... 41.4 

.04 do.... 37.5 

.02 do.... 40.9 

1 do.... 36.2 

3 do.... 38.9 

5 do.... 36.4 

7 do.... 39.6 

9 do.... 14.7 

Color after burning Grood buff from cone .010 to cone 7. Gray 

at cone 9. 

Hardness Soft from cone .010 to cone 7. Steel hard 

at cone 9. 

Best burning temperature 1,300** C. 

Remarks This clay is favorable for soft building 

brick, having a good color. It has an 
abrupt temperature range. There is 
little change in porosity from cone .010 
to cone 7. 


On Big Walnut Creek about 6 miles northeast of Austin, and about 
one-fourth of a mile north of the Manor-Austin road, occurs a good 
outcrop of the Taylor marl, the clay of which at this point is suitable 
for the manufacture of soft building brick. The location is indicated 
by No. 426 on Plate VI (p. 302). 

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In the bluff on the creek at this point there is exposed some 40 feet 
of calcareous, massive blue shale. This shale is very uniform in 
chemical and mineralogical composition over a considerable area; 
the grain is medium fine and the hardness about 2 on the Mohs scale. 
Back from the top of the bluff there is a somewhat sharp and abrupt 
slope to the divide, the elevation increasing about 150 feet in a dis- 
tance not exceeding one-fourth of a mile. This slope, all of which is 
underlain by the clay, is covered with a veneer of black soil, contain- 
ing quartz and flint pebbles that average 2 inches in diameter; the 
average thickness of this overburden is about 2 feet. The slope is 
covered with a thin growth of mesquite. Altogether 30 to 40 acres 
of clay is available here that can be worked on a face at least 25 feet 
in vertical extent. 

This locality presents a favorable opportunity for the establish- 
ment of a plant where brick can be manufactured very economically. 
The particular advantages are, first, the great body of clay available 
of uniform character and under slight cover; second, the ease with 
which a clay pit could be kept free of water by draining it into Big 
Walnut Creek; third, the fact that the topography permits the pit 
to be located on higher ground than the yard, so that clay can be 
dehvered to the yard by a gravity system, loaded cars pulling up the 
empties; fourth, the excellent transportation and market facilities, 
this deposit being located alongside the main line of the Missouri, 
Kansas & Texas Railway and 2 miles from the Houston-Austin 
division of the Houston & Texas Central Railroad; and fifth, the 
nearness of Austin, a good market town and distributing point for 

For water, an impounding reservoir would have to be built. For 
fuel, lignite would probably prove to be the most economical, sup- 
pKed by the mines at Phelan, Bastrop County, and Rockdale, Milam 
County. Labor will cost about $1.50 a day. 

Burning tests made on this clay indicate that it will bum steel hard 
at a comparatively low temperature and to a good buff color. Its 
drying behavior is fair. The details of these tests foUow: 

Burning behavior and physical properties of clay belonging to the Taylor marl on Big 
Walnut Creek near Au^Hn {No. 425). 

Description of raw clay Calcareous blue shale, massive, medium 

fine grained. 

Molding behavior Good working plasticity. 

Drying behavior Fair. 

Drying shrinkage: 

Per cent of wet length 10. 6 

Per cent of wet volume 31. 20 

Burning shrinkage, per cent of wet length . . 4.3 
Total linear shrinkage, per cent of wet 
length 6.2 

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Poroeity at cone .010 per cent. . 22. 5 

.08 do.... 27.20 

.06 do.... 25.50 ' 

.04 do.... 24.8 

.02 do.... 26.90 

1 do.... 16.0 

3 do.... 23.80 

Color after burning Good buff. 

Hardness Steel hard from cone .06 to cone 5. 

Beetbinming temperature 1,190® C. 

Remarks This clay is suitable for soft building brick, 

having a good color. 

The following is a chemical analysis of this clay made by the 
chemical laboratory of the Geological Survey: * 

AruHyns of clay from east bank of Big Walnut Creek 6i miles northeast of Austin. 

Silica (SiOa) 36.08 

Alumina ( AljO,) 18. 64 

Ferric oxide (FeaOj) 4.14 

Manganese oxide (MnO) 01 

Lime(CaO) 17.39 

Magnesia (MgO) 1.74 

Sulphur trioxide (SO3) 1. 59 

Soda(NaaO) 19 

Potash ( K3O ) 1. 49 

Water at lOO** C 3.09 

Loss on ignition 15. 77 

100. 13 

Half a mile east of Watters station, on Big Walnut Creek, in Travis 
County, occurs a good outcrop of shale belonging to the Eagle Ford 
clay, a formation of the Upper Cretaceous or Gulf series. The portion 
exposed here represents the upper part of this formation. This shale 
was sampled in order to determine its value for the manufacture of 
burned products. The location is shown by No. 427, Plate VI. 

This shale is a dark-blue, fine-grained, hard, laminated shale, of 
marine origin, having been deposited in shoal water in the Cretaceous 
sea. It carries a slight percentage of bituminous matter. The shale 
is 15 feet thick and is overlain by 10 feet of limestone gravel. 

This shale is very uniform in chemical and physical composition 
over the available area, which includes some 10 to 20 acres. The 
working face of the quarry or pit would average 10 feet. The shale is 
exposed by reason of the occurrence of a small fold which crosses the 
creek here and which has elevated the clay some 15 to 20 feet above its 
normal position. Some pyrite nodules are distributed throughout the 

1 BuTCbard, E. F., Structural materials available in the vicinity of Austin, Tex.: Bull. U. 8. OeoU 
Survey No. 430, 1910, p. 81£. 

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mass of the shale, but they could be readily removed by hand in 

The overburden of limestone gravel could be disposed of for railroad 
ballast or road building at a price that would at least pay the cost of 
removal. By not working too deep in the clay, water in the pit could 
be drained into Big Walnut Creek by gravity or by siphoning. The 
deposit is situated half a mile east of the Llano division of the Hous- 
ton & Texas Central Railroad and about 1^ miles east of the main line 
of the International & Great Northern Railroad. At the base of the 
!Eagle Ford formation, at a depth of 40 feet below the bed of the creek, 
occur some sandy beds which carry a heavy, black asphaltic oil. The 
wells put down to these beds can be bailed at the rate of 10 barrels a 
day. It is possible to distill asphalt from this oil, and the fractions 
could be used as a source of fuel for any manufacturing plant that 
might be established here. Aside from this possible fuel, lignite and 
wood are available at prices averaging $1.25 a ton and $3 a cord, 
respectively. Labor can be had at prices averaging $1.50 a day. 

Burning tests made on this clay show it to possess good molding and 
drying quahties. In addition it burns steel hard and to a good buff 
color at a reasonably low temperature. However, the range of tem- 
perature between the points of incipient fusion and viscosity is lower 
than is desirable, so that there is danger of overbuming and fusing a 
considerable part of a kiln before the other parts have attained a steel- 
hard condition. For this reason the clay would have to be handled 
very carefully in burning. The details of the burning tests follow: 

Burning behavior and physical properties of clay near Walters, Travis County {No. 4t7), 

Description of raw clay Dark, fine-gcained, hard shale. Grinds eas- 
ily in pan to 10 mesh; no detritus. 

Molding behavior Plasticity good; works well on machine; 

little lamination. 

Drying behavior Good; no warping or cracking. 

Drying shrinkage: 

Per cent of wet length 6.28 

Per cent of wet volume 15. 66 

Burning shrinkage, per cent of dry length. . 7.9 
Total linear shrinkage, per cent of wet 

length 14.18 

Porosity at cone . 010 per cent. . 63- 1 

.08 do.... 64.8 

.06 do.... 64.8 

.04 do.... 59.6 

.02 do..-. 60.6 

1 do.... 62.3 

3 do.... 58.7 

5 do.... 21.7 

7 do.... 

(Dolor after burning Good buff. 

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Hardnees Soft until it reaches cone 5, where it be- 
comes steel hard. 

Best burning temperature 1,230® C. 

Remarks A very abrupt drop at cone 5 makes the 

material somewhat unsafe for commercial 


On the Herman Opperman farm^ about 2^ miles north of Lyons, 
Burleson County, and about one-foTirth mile southwest of the main 
line of the Gulf, Colorado & Santa Fe Railway, occurs a deposit of 
green compact shale. This deposit (No. 380, PI. VI) occurs appar- 
ently in the upper portion of the Cockfield formation of the Eocene 
Claiborne group, close to the base of the Jackson formation. 

On a small branch leading into Davidson Creek 6 feet of the shale 
is exposed, overlain by 2 feet of black clay soil with a small quantity 
of quartz and flint gravel intermixed and underlain by gray sandstone 
carrying water. This clay is very uniform in chemical and physical 
composition and shows no discoloration on the joint and fracture 
planes, along which water was circulating at the time of the writer's 
inspection. The hardness is between 2 and 3 on the Mohs scale. 

M. M. Graves, of Somerville, has prospected this deposit by means 
of drill holes, and states that it occurs, in a form similar to that seen 
on the outcrop, over 30 acres of this farm, varying in thickness from 
6 to 7 feet. 

The dip of the clay is to the southeast, and in this direction the 
amount of overburden increases. The average thickness of the over- 
burden over the entire area of available clay is 4 feet. This deposit 
IS very favorably situated with respect to facilities for drainage, 
transportation, and working. The conditions as regards labor and 
fuel are similar to those for other clays in the general vicinity of 

It is thought that this clay may possess value as a fuller's earth 
(see report on clay No. 381, p. 343) and some tests have been made 
to determine its bleaching and decolorizing properties. Tests iadicate 
that the clay is only fairly satisfactory for the manufacture of burned 
products. Great difficulty is experienced in drying the clay, it being 
found to crack badly. Its burning behavoir is very satisfactory, and 
perhaps the addition of a slight quantity of sand would correct the 
poor drying qualities and render the clay useful in the manufacture 
of dry pressed brick. The results of these tests appear below. 

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Bttming behavior and physical propertiea of clay on Opperman famtf 2\ miles north of 

Lyons (No. 380). 

DeBcription of raw clay Green shale, fine grained, massive; ground 

nicely, no detritUB. 

Molding behavior Good working plasticity. 

Drying behavior AU pieces cracked. Volume pieces made 

in hand mold. 
Drying shrinkage, per cent of wet length . . 9. 9. 

Porosity at cone . 010 per cent. . 17. 1. 

.08 do.... 5.6. 

.06 do 5.7. 

.04 do 3.2. 

.02 do.... 6.1. 

1 do.... 4.8. 

3 do.... 3.7. 

5 do.... 4.9. 

7 do.... 4.3. 

9 Blue stone, draw trials checked. 

Color after burning Reddish at cones .010, .08, and .06; bu£E 

at higher temperatures. 

Hardness Remarkable hardness. Steel hard at cones 

.010 to 7. Not glassy. 

Best burning temperature 1,150® to 1,260'* 0. 

Remarks This clay has a remarkable vitrification 

range, with faiily low porosity; no glassi- 
nees. It has poor drying quality; other- 
wise it would be suitable for brickmaking. 


About 1 mile north of Canxiine, in Washington County, on the f ann 
of John Derrick (post office, Carmine), occurs a considerable body of 
green calcareous shale that was thought to possess value for the 
manufacture of burned products. It appears from the results of the 
tests, however, that this clay is not adapted for the manufacture of 
such wares, being impossible to dry without cracking. Further, it 
does not mold satisfactorily and is very unsatisfactory in burning 
behavior. The location is indicated by No. 396 on the map (PI. VI)^ 

This clay carries vertebrate fossils of Miocene age. It is evidently 
of lacustrine origin, having been deposited probably in shallow lakes 
adjacent to the shore in early Miocene time. 

The clay is very well exposed for about a mile in the banks of a 
small creek that crosses this farm. At one point on the creek there is 
exposed 10 feet of green calcareous shale. About a mile higher up 
the creek at the crossing of the Burton-Carmine road, the thickness 
exposed is estimated at 10 feet and the shale is overlain by 5 feet of 
brown soil (alluvium). 

This shale is of uniform chemical and physical composition through- 
out. At the surface it weathers into a brown shale; its hardness is 
about 2, and it has a pearly luster. 

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A considerable body of clay is available here, at least 100 acres. 
The overburden may average 5 feet, but few data are available on 
this point. The country is sublevel, cut by canyon-like ravines and 
covered with sandy soil and post-oak timber. Natural drainage for 
a clay pit would be available. The deposit could be reached by a 
spur 2 miles in length from the Austin branch of the Houston & Texas 
Central Railroad. The economic conditions governing the exploita- 
tion of this deposit — such as the availability and cost of fuel, water, 
and labor — are in general similar to those indicated for the clay deposits 
in the vicinity of Burton. 

This clay may possibly possess value as a fuller's earth, though 
no tests to determine this point have thus far been made. The results 
of the burning tests appear below. 

Burning behavior and phygical properties of clay on the John Derrick /army near Carmine 

(No. S96), 

Description of raw clay Green calcareous shale. Grinds easily. 

Molding behavior Laminated badly; works very poorly on 


Drying behavior Impossible to dry; cracks and warps badly. 

Porosity at cone . 010 per cent. . 25.40. 

.08 do.... 19.60. 

.06 do 8.70. 

.04 do.... 4.80. 

.02 do.... 3.60. 

1 do 4.60. 

3 do 4.80. 

6, 7 do Vesicular. 

Color after burning do Buff at lower temperatures; red at higher 


Hardness Steel hard from cone .010 to cone 3. 

Best burning temperature 1,150® C. 

Remarks Very unsatisfactory as to working befaayior, 

drying, color, and burning. Becomes 
vesicular above cone 2. Mjasurementof 
drying and burning shrinkages not ob- 


About half a mile south of the courthouse at Caldwell, in Burleson 
County, occurs an extensive body of gray, very plastic shale. The 
property belongs to A. B. Duckworth, of Caldwell, and the location is 
indicated on Plate VI by No. 376. 

This shale is a member of the Cook Mountain formation of the 
Eocene Claiborne group. Its marine origin is proved by the occur- 
rence of marine fossils in the clay. 

The clay is well exposed in the banks of erosion hollows on this 
tract, and its thickness, as shown by these exposures, is at least 10 
feet. The clay is available over 4 or 5 acres of ground. In this area 

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the overburden, which consists of a reddish-brown clay soil, will aver- 
age 2 feet. 

This shale weathers into a plastic brown clay, the color being due 
to the oxidation of the iron, which is apparently present- in consider- 
able quantity. In the bed sampled the clay was partly weathered 
and presented a mottled appearance, gray and brown specks making 
up the mass. 

The deposit is 100 yards east of the main line of the Gulf, Colorado 
& Santa Fe Railway. A clay pit here could be readily drained by 
gravity. Water suitable for generating steam can be had in is^eUs 
not exceeding 300 feet in depth. Lignite can be delivered from the 
mines at Milano and Rockdale, at a cost not over $1.25 a ton. Labor 
will command SI. 50 a day. 

The results of burning tests made on this clay indicate that it is 
not well adapted for the manufacture of clay products. It is difficult 
to mold, warps and cracks in drying, is difficult to oxidize, and bums 
to an unsatisfactory chocolate color. The details of these tests appear 

Bvming behavior and physical properties of shale on the Duckworth property at Caldwell 

{No, S76). 

Description of raw clay Soft, partly weathered gray shale. Grinds 


Molding behavior Plastic and sticky. Works poorly on 

auger machine. Column torn. 

Drying behavior Warps and cracks. Volumeter pieces 

cracked. Made up by hand. 
Drying shrinkage : 

Per cent of wet length 9.02 

Per cent of wet volmne. . . .' 36. 50 

Burning shrinkage, per cent of dry length . . 6. 6 
Total linear shrinkage, per cent of wet 

length 15.62 

Porosity at cone .010 per cent. . 9. 3 

.08 do.... 8.4 

.06 do.... 7.10 

.04 do.... 8.30 

.02 do.... 5.70 

1 do.... 9.50 

3 do.... 12.10 

5 do.... 9.0 

7 do.... 

Color after burning Unsatisfactory chocolate color. 

Hardness Vesicular at cone 1. Steel hard from cone 

.010 to cone 5. 

Best burning temperature 1,100° C. 

Remarks Gives trouble in cracking and burning. 

Difficult to oxidize. Has a fairly con- 
stant porosity until it reaches cone 1, 
when a vesicular structure is developed. 

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Just south of the Missouri, Kansas & Texas Railway bridge on 
Piney Creek at Bastrop, Bastrop County, occur terrace clays from 
which brick were formerly burned. The location of this deposit is 
indicated by No. 355 on Plate VI (p. 302). 

This clay is of alluvial origin, having been deposited by Colorado 
River in its former flood plain in late Pleistocene times. It repre- 
sents reworked Permian d6bris brought down by the river from the 
Permian area in northwestern Texas. The clay is brown and con- 
tains a large percentage of sand, being very lean. 

The bluff at this point exposes some 20 feet of this clay. A consid- 
erable body of material is available — 30 or 40 acres. Owing to the 
alluvial origin of this clay, it is likely to vary in chemical and mineral- 
ogical composition, but within the immediate area observed, where it 
is exposed along the bluff for a distance of at least half a mile, it 
appears to the eye to be fairly uniform in physical make-up. lime 
concretions appear in it here and there. No overburden need be 

A clay pit here could be easily drained by a gravity system. The 
area is said to be not subject to overflow, and it is apparently well 
above high-water mark. The deposit is but 200 yards distant from 
the main line of the Missouri, Kansas & Texas Railway, and the con- 
struction of a siding would be a simple matter. Lignite can be had 
from the mines at Phelan, 5 miles distant by rail. No timber need 
be removed. Water can be had from the river and from shallow 
wells. Labor will command $1.50 a day. As a distributing point, 
however, Bastrop is not to be highly commended. 

A small local brick yard was formerly operated here by Al. Jung. 
The brick burned, as inspected by the writer, were good hard brick of 
a reddish-yeUow color. The brick were burned for local consump- 
tion only. 

The results of tests on this clay indicate that it molds satisfactorily, 
dries without cracking, bums steel hard at cone 5, and bums to a good 
buff color. On the other hand, the range of temperature between the 
points of incipient fusion and viscosity is very small, which would 
result in the overbuming of a good many brick in a kiln, so that this 
clay can not be regarded as suitable for the manufacture of building 
brick. The details of these tests follow: 

Burning hehav^ior and physical properties of alluvial clay at Bastrop {No. 355). 

Description of raw clay Brown, sandy, alluvial clay; grinds easily. 

Molding behavior Good working plasticity; sandy. 

Drying behavior Very good. 

Drying shrinkage: 

Per cent of wet length 3. 96 

Per cent of wet volume 14. 26 

B uming shrinkage , per cent of dry length . . 

Digitized by VjOOQIC 


Total linear ahzinkage, per cent of wet 

length '. 3.96 

Poroaity at cone . 010 per cent. . 49. 20 

.08 do.... 42.20 

.06 do.... 42.80 

.04 do.... 34.80 

.02 do.... 43.00 

1 do.... 42.30 

3 do.... 40.70 

5 do.... 0.4 

7 do Fusing. 

Cx>lor after burning Good buff. 

HardnesB Soft from cone .010 to cone 3; steel hard at 

cone 5; vesicular at cone 7. 

Best burning temperature 1,170® C. 

Remarks This clay has a very good working and dry- 
ing behavior and a fine color, but the sud- 
den drop in porosity between cones 3 and 
5 would be unfavorable for working in 
conmiercial kilns. 


On the Burkhart land, 2^ miles northeast of Ledbetter, in Wash- 
ington County, occurs an extensive deposit of soft, white laminated 
clay (No. 402, PI. VI). This clay is apparently of palustrine origin, 
haying been deposited in a swamp adjacent to the shore in Jackson 
time. The deposit appears to be much more extensive than the 
others of similar nature in this region. 

On the headwaters of Turkey Creek the following section is exposed 
in the bank of the creek: 

Section on Turkey Creek t\ miles northeast of Ledhetter, 

Ft. fa. 

1. Gravel (Pleistocene) 6 

2. Gray laminated sand 5 

3. White clay, laminated 6 

4. Brown lignitic shale 2 

13 6 

The clay (No. 3 of the section) is soft, its hardness being about 1.5 
on the Mohs scale. On the face of the bed there is a slight tint of 
yellow discoloration, indicating the presence of iron. Otherwise the 
clay appears to be of uniform chemical and physical composition 
over a considerable tract of land. 

A deposit of identical character, 7 feet thick, was found at a depth 
of 30 feet in the shaft at the lignite mine near Ledbetter, 2 miles west 
of this point. J. W. Hackworth, of Ledbetter, informs the writer 
that in the shafts put down to determine the extent of the lignite 
which underlies the white clay in this vicinity a similar bed of clay 
was passed through. Apparently, therefore, this clay covers an 

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extensive area, but it doubtless lies under too heavy a cover to be 
valuable over all of this area. Doubtless, however, a tract can be 
located in which the overburden should not average more than 6 
feet in thickness and will consist chiefly of gravel, which can be used 
for ballast, and clay. 

The general geographic, physical, and economic conditions for this 
deposit are similar in all respects to those outlined for clay No. 404 
(p. 349). 

Tests were made to determine the value of this clay for the manu- 
facture of burned products, but the rapidity with which it fuses and 
its low plasticity would seem to render it unsuitable for commercial 
work. The results of these burning tests appear below: 

Bvming behavior cmd physical properties of clay on the Bwrhhart land, t\ miles northeast 

o/Ledbetter {No. 402). 

DeBcription of raw clay Soft, white laminated clay; grinds easily. 

Molding behavior Very low plasticity and short; column torn 

at comers. 

Drying behavior Good. 

Drying shrinkage: 

Per cent of wet length 6. 35 

Per cent of wet volume 18. 68 

Burning shrinkage, per cent of wet length. 19. 20 
Total linear shrinkage, per cent of wet 

length 25.55 

Porosity at cone . 010 per cent. . 39. 4 

.08 do.... 31.7 

.06 do.... 17.4 

.04 do.... 0.3 

.02 do.... 

1 do.... 

Color after burning Buff. 

Hardness Soft at cones .010, .08, and .06: vitreous 

above cone .04. 

Best burning temperature 1,070® C. 

Remarks The clay has a short temperature range and 

would be unsuited for commercial work 
of any kind. All draw trials from cone 
.06 to cone 7 were shattered in being 
drawn from the kiln. 


Three-fourths of a mile northwest of the courthouse at Caldwell, 
Burleson County, occurs a deposit of residual weathered sandy clay, 
from which brick have been burned for local use at Caldwell. The 
clay is a surface clay derived from the underlying Cook Mountain 
formation, the particular member occurring here being a red sandy 
clay, probably of palustrine origin. This surface clay is 6 feet thick 
over an area estimated at 15 acres. It is covered with a foot of sandy 

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soil; which supports a thin forest of post oak. So far as could be 
ascertained the material is fairly uniform in chemical and physical 
composition. A pit here could be drained without pumping. The 
deposit lies half a mile east of the main line of the Gulf, Colorado & 
Santa Fe Railway, and could be readily reached with a spur. The 
situation as regards fuel, labor, and water is similar to that of the 
other deposit near Caldwell, described above. 

Tests indicate that this material is not classifiable as a clay because 
it will not mold, being too high in sand, and because it can not be 
burned to a steel-hard condition. - The material may be useful as a 
molding sand, but no tests have been made to determine its value for 
this purpose. The results of the burning tests appear below: 

Btaming behavior and physical properties of clay northweai of Caldwell {No. S75). 

Demrription of raw clay Biown sandy clay; friable. 

MoldiBg behavior Not a clay; aimilar to molding sand; made 

up in hand molds. 

Drying behavior Good. 

Porosity at cone .010 per cent. . 36. 60 

.08 do.... 36.30 

.06 do.... 36.30 

.04 do.... 36.40 

.02 do.... 35.90 

1 do.... 36.20 

3 do.... 36.50 

5 do.... 36.40 

7 do.... 35.10 

Color after burning Red. 

Hardness Soft. 


Three miles north of Somerville^ Burleson County, and 1 mile west 
of the main line of the Gulf, Colorado & Santa Fe Railway, is located 
the plant and clay pit of the Somerville Fuller's Earth Co. (No. 382, 
PLYI). In the pit there is exposed some 12 feet of brown fuller's 
earth, which dips beneath hard gray sandstones not over 200 feet 
from this point. Geologically this fuller's earth occurs ia the upper 
portion of the Jackson formation. 

This deposit is known to cover some 50 acres and is available over 
all of this area. It has been carefully prospected and surveyed, but 
the results of the borings are not known. Over most of this area the 
clay is covered with 3 to 10 feet of brown loamy soil and gravel, 
which in some places is underlain by a gray sandstone on top of the 
fuller's earth. 

The fuller's earth itself is a fine-textured, compact, even-grained, 
hard brown clay, with hardness varying between 2 and 3 on the Mohs 
94174*— BuU. 470—11 22 

Digitized by 



scale. The bed dips slightly to the south. Joint and fracture planes 
are numerous and along these planes, as well as the lamination planes, 
there is visible a slight coating of limonite, deposited by the action 
of circulating water. The clay also contains a few nodules of pyrite 
averaging three-fourths of an inch in diameter. 

The topography in this vicinity is generally sublevel, though there 
are some ridges and hills formed by the relatively hard gray sand- 
stones. Most of the area is covered by a veneer of the Pleistocene 
terrace gravels, made up of quartz, flint, jasper, and limestone cob- 
bles and pebbles. In places this gravel is covered by a plastic brown 
clay-loam soil of the Lufkin soil series. The region is generally for- 
ested with post oak. 

For fuel, lignite from the mines at Milano and Rockdale is availa- 
ble, as well as the cordwood that can be cut ia this vicinity. Water 
satisfactory for steaming can be had in wells not exceeding 500 feet 
in depth. Natural drainage can be depended on to keep the pits 
free from water. 

This deposit was worked for a brief period in 1909 and 1910, the 
clay being manufactured and marketed as fuller's earth. An SSO^GOO 
plant was erected here in 1909, but it proved a failure. The clay 
was dried and then crushed to a fineness of 80 to 200 mesh. It is 
asserted that one of the causes of failure was that the company was 
preparing too fine a product, earth of 90 mesh being the grade that is 
commonly used in bleaching or decolorizing ordinary oils. Another 
disadvantage was the lack of a spur connecting the plant with the 
railroad, so that the prepared earth had to be hauled by wagon 3 
miles to the nearest shipping point. Under these circumstances, it 
cost about $14 a ton to deliver the fuller's earth in Chicago. The 
market price in Chicago varies from $14 to $18 a ton. Under favor- 
able working conditions, on a deposit properly located and with ade- 
quate shipping facilities, this earth could probably be delivered in 
Chicago at $10 a ton. 

Mexicans and white men were employed as hands at a cost of $1.60 
a day. The quarrying methods were very simple. The clay was 
dug with picks, shoveled into wagons, and then hauled to the mill, 
about 700 feet distant from the pit. It cost $1.50 a ton to haul the 
prepared earth from the mill to the cars. The freight rate to Chicago 
ia $6.75 a ton. Twenty per cent of the net proceeds was paid to 
the owners of the land as a royalty. The capacity of the plant was 
one-third of a car, or 6 tons, a day. 

After the shipment of a few cars of the earth, which it was found 
very difficult to market, work was discontinued and the plant is now 
idle. If the earth had been properly bolted and the finer material 
separated from the coarser in a way to suit the demands of the trade, 
it would doubtless have found a ready market. It is believed that 

Digitized by 



if plants are located properly and intrusted to experienced men, these 
deposits can be profitably worked. 

The Survey has not yet completed any tests to determine the value 
of this clay when used as fuller's earth, but such tests are now in 
progress, and the results will be available for publication sometime 
during the present year. Tests were made on this clay to determine 
its burning properties, but the results seem to indicate that it has no 
value for the manufacture of burned products. 

Burning behavior and pkytioal propertiea of clay at SomervUle fuller^s earth plants S 
-milea north of SomervUle (No. S82). 

Description of raw clay Light-brown, fine-grained shale. Grinds 

easily with no detritus. 

Molding behavior Ftdler's earth. Extremely plastic and 

sticky. Works unsatisfactorily in ma- 
chine. Laminated structure. 

Drying behavior All pieces warped and cracked; pieces made 

by hand cracked. 
Drying shrinkage: 

Per cent of wet length 12. 41 

Per cent of wet volume 38. 30 

Burning shrinkage, i>er cent of dry length . . 5. 7 
Total linear shrinkage, per cent of wet 

length lail 

Porosity at cone .010 per cent. . 21. 3 

.08 do.... 6.20 

.06 do 9.3 

.04 do.... 7.1 

.02 do.... 3.5 

1 do.... 3.6 

3 do.... 5.0 

5 do.... 7.7 

3, 5, 7, 9 Becoming swelled. 

Color after burning Very poor red color. 

Hardness Soft at cone .010, steel hard at higher tem- 

Best burning temperature 1|150^ 0. 

Remarks This clay unsatisfactory 83 to working prop- 
erties, drying behavior, color, etc. Could 
not be used in the manufacture of clay 


Seven miles north of Burton, on the David Heirs League, in Wash- 
ington County, are located the plant and pit of the Texas Fuller's 
Earth Co. (No. 393, PI. VI). At this place fuller's earth was manu- 
factured and a small quantity was shipped in 1909. 

The deposit is a soft brown fuller's earth representing a deposit 
laid down in a lagoon adjacent to the shore in late Jackson time. It 
covers some 250 acres of ground, its occurrence over this territory 

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having been proved by borings and systematic prospecting. At the 
pit the following section is exposed: 

Section at pit of Texas FuUer'a Earth Co., near Burton, 


1. Sand with inteistratified clay seams 2 inches thick; overburden . . 10 

2. Soft brown fuller's earth 4 

3. Lignitic shale i 

4. Soft brown fuller's earth 5 

Thus far stratum No. 2 has been the only one worked for fuller's 

A drill hole about 300 feet north of this pit is reported to have 
passed through the following beds: 

Section of drill hole north of Burton. 



Ft. in, 

1. Material not given; orerborden i 6 

2. Dark-red,"asphalt-bearing" clay (probably lignite) 1 

8. Dark-red. fuUer's earth 7 10 

4. Soft sandstone 6 

6. Gray fuller's earth 5 

& Sandstone 4 

7. Lignite i 6 

8. Gray, slate-like shale , 4 

9. Softsandstone i 7 2 

10. White fuUer's earth , 3 

11. Clay, carrying a great mass of silicUied wood, made up almost entirely of silicified wood. 6 

12. Sandstone i 4 6 

13. Water-bearingsandyCarryinggood drinking water | i 

14. Softsandstone i 15 

16. Water-bearing sand, yielding sulphur water i 4 

16. Lignite i C 

17. Shale ! 2 

18. Quicksand i 4 

19. Sandstone i 2 

20. Water-bearing sand, yielding abundant supply of good water 2 

Ft. iu. 


14 10 

15 4 
20 4 
24 4 
24 ID 




The lignite numbered 16 in the section above was found to be 38 
inches thick at a depth of 36 feet in drill hole No. 17, about 300 feet 
southwest of the pit. Drill holes Nos. 10 and 11, 300 and 350 feet, 
respectively, west of the pit, struck this bed of lignite at 44 feet below 
the surface, hole No. 10 showing 6 feet of lignite and hole No. 11 
4 feet. 

Drill hole No. 8, about 300 feet northeast of the pit, showed 5 feet 
of overburden above 7J feet of the fuller's earth. Drill hole No. 3, 
about 60 feet N. 10® E. from hole No. 8, showed 6 feet of overburden 
on top of 6 feet of fuller's earth. Drill hole No. 4, about 75 feet 
east of hole No. 3, showed 7 feet of overburden on top of 5 feet of 
fuller's earth. Drill hole No. 5, about 100 feet east of No. 4, showed 
7 feet of overburden on top of 4^ feet of fuller's earth. Drill hole 
No. 10, 375 feet northwest of hole No. 17, showed 4 feet of over- 
burden on top of 7 feet of fuller's earth. Drill hole No. 11, about 
100 feet east of No. 10, showed 5 feet of overburden above 7 J feet of 
fuller's earth. Drill hole No. 12, about 200 feet east of No. 11, 
showed 5i feet of overburden on top of 7^ feet of fuller's earth. 


zed by Google 


The results of these drilliugs, as well as others, seem to show that 
tliere is available here, over 200 acres of ground or more, a bed of 
fuller's earth averaging 5 feet in thickness, covered with an over- 
burden of soil, gravel, and clay that will average 6 feet in thickness. 

The topography in this vicinity is generally sublevel, the creeks 
and drainways flowing in small canyons and hollows. The area is 
veneered wiUi a thin coat of Pleistocene gravel, consisting of quartz, 
flint, jasper, etc. In places this gravel is covered with a brown 
plastic loam of the Lufkin soil series and the region is generally 
covered with a growth of post oak. 

Burton, 7 miles distant on the Houston & Texas Central Railroad, 
is the nearest shipping point. The plant is not connected with the 
railroad by a spur, and it has been necessary to haul the prepared 
earth to Burton by wagon. For this reason the operations proved 

The existence of lignite in this locality that can be mined for fuel 
has already been mentioned. The nearest lignite mines are those at 
Ledbetter, some 15 miles distant. During the period of operation, 
however, wood was used for fuel, being cut from this and adjacent 
land and delivered at the plant at prices, it is stated, averaging SI a 
cord. This price does not cover the stumpage value of the wood. 
Water can be drawn from wells. To furnish a supply for generating 
steam at this plant, however, a storage reservoir was built and 
surface water was impounded. Drainage of the pits was secured 
by a natural system, without resort to pumps, the bottoms of the 
pits lying generally higher than the main creeks. 

This deposit was worked only for a period of a few months in 
1909. A $47,000 plant was erected here. It was soon found that 
operations were being conducted at a loss and work was suspended. 
The mill is equipped with drying and pulverizing machinery, one 
burr mill being used. The grinding machinery is capable of reduc- 
ing the clay to a size varying from 40 to 200 mesh. Labor was 
supplied by negroes at a cost of $1 to $1.25 a day. There were no 
especial quarrying facilities, the clay being dug from the pit by pick 
and shovel and hauled to the mill by wagons. 

The failure here was doubtless due to the unsatisfactory location 
of the plant. The cost of working clay under 6 feet of overburden 
was excessive, and to this was added the cost of hauling the prepared 
earth 7 miles to a shipping point and hauling back supplies. The 
poor location is especially open to criticism because deposits of fuller's 
earth of as good quality can be found in this State practically adja- 
cent to railroads, and without an excess of overburden. Tests to 
determine the value of this clay when used as fuller's earth have not 
yet been completed. The results given below show that this mate- 
rial is not adapted for the manufacture of burned products. 

Digitized by 



Burning behavior and physical properties of the clay from the pit of the Texas Fuller^ s 
Earth Co., 7 miUs north ofB-wrtjcm (No. S93), 

Deecription of raw clay Soft ligjit-brown fine-grained shale; grinds 


Molding behavior Puller's earth, very, plastic; works poorly 

on machine. 

Drying behavior Impossible to dry; cracks and warps; all 

pieces made by hand and on machine 

Porosity at cone .010 per cent. . 32. 00 

.08 do.... 17.90 

.06 do.... 17.20 

.04 do.... 8.20 

.02 do.... 8.40 

1 do.... 5.9 

3 do.... 3.80 

5..... do.... 5,5 

7,9 do Vesicular. 

Color after burning Very unpleasant red color. 

Hardness Increasing hardness from cone .010 to 

cone 3; vesicular at cone 5. 

Best burning temperature 1,190® C. 

Remarks Not adapted to the manufacture of clay 

products. Has unsatisfactory working, 
drying, and burning behavior, and a 
poor color. 



Five miles south of West Point, on lot 84, W. F. Hamilton League, 
in Fayette County, on land belonging to J. C. Melcher, of O'Quinn, 
is another considerable deposit of fuller's earth. (See PL VI, No. 
432, and PL VII.) All of the area marked on Plate VII as being 
underlain by lignite also contains this bed of brown fuller's earth, 
ranging in thickness from 6 to 16 feet and lying imder 2 to 10 feet of 
overburden. A large body of this earth is available. 

On lot 84 of the W. F. Hamilton League, along the banks of a 
small hollow, this fuller's earth is well exposed, showing a section 16 
feet in thickness, very uniform in physical and chemical composition, 
overlain by 2 feet of Pleistocene gravel. The gravel could be utilized 
for ballast, and a plant at this point could be operated very eco- 
nomically as there is little overburden, the clay is present in a very 
thick bed, natural drainage facilities are available, wood and lignite 
are abundant, and the deposit is but half a mile from the San Antonio 
& Aransas Pass Railway. 

This earth is of a light-brown color, a very fine, almost compact 
texture, and a hardness between 2 and 3 on the Mohs scale. A 
slight film of limonite appears on the joint and lamination planes. 

The results of tests to determine the value of this material as 
fuller's earth are not yet available for publication. Mr. Melcher 

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makes the following statement in regard to certain tests made on 
samples collected by him: 

This * * * fuller's earth * * * was tested in May, 1908, by the State of 
Texas, at College station, Texas, in connection with a number of earths from different 
deposits in Texas, and in comparison with the standard imported English earths of 
100 points bleaching powers for cotton oil. The Melcher No. 1 M. B. went as high as 
224 points, and the Melcher No. 1 M. went as high as 207 points, with no bad tastes or 
bad odoiB, nor changes in colors after standing two weeks exx>osed to open atmosphere. 

Tests made by this Survey show that this clay is not adapted for 
the manufacture of burned products. The results of these tests 

Burning behavior and physical properties of the clay on the Melcher property south of West 

Point {No. 4S2), 

Description of raw clay Brown, medium, fine-grained shale; grinda 

Molding behavior Very plastic and sticky; gives smooth col- 
umn on machine; laminated structure. 

Drying behavior Warps and cracks on drying in air. 

Drying shrinkage: 

Per cent of wet length 11. 68 

Per cent of wet volume 36. 65 

Burning shrinkage, per cent of dry length. 7. 7 
Total linear shrinkage, per cent of wet 

length 19.28 

Porosity at cone .010 per cent. . 32. 10 

.08 do.... 27.00 

.06 do.... 18.60 

.04 do 6.30 

1 do.... 4.70 

3 do.... 2.10 

5 do.... 4.60 

3, 5, 7, 9 Becoming vesicular. 

Color after burning Unsatisfactory buff color. 

Hardness Good hardness from cone .06 to cone 5; 

vitreous at cone 5. 

Best burning temperature 1,190® C. 

Remarks Vesicular structure developed; high dr3ring 

shrinkage; gives trouble by cracking dur- 
ing burning. 


On the J. C. Murray farm, 3 miles north of Lyons, Burleson County, 
occurs a hard blue shale that may be tentatively classed as fuller's 
earth. The location is indicated on Plate VI by No. 381. This shale 
occurs in the upper portion of the Cockfield formation, apparently, 
lying just beneath the Jackson formation. This bed immediately 
overlies the clay of the Opperman property (No. 380), which dips 
beneath it. 

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On a branch of Davidson Creek a shaft put down by Mr. Murray 
exposes the following beds, as noted by the writer: 

Section in Murray shirft, near Ly<m», 



1. Soil, with gravel Interspersed 

2. Blue shale, same bed as clay on Oppennan property (No. 380) 

8. Grey sandstone 

4. Blue shale, same as No. 2 

5. Grey sandstone , same as No. 3 (this sandstone does not appear in the shaft 135 feet south 

of this one , havbig pinched out) 

0. Blue shale or fuller's earth , 

7. Sandstone, not penetrated , 

Ft. in. 
8 7 


Ft. in. 


7 8 

8 8 
18 8 

Bed No. 6 consists of a compact blue shale, of uniform chemical and 
physical composition, with hardness between 2 and 3. The joint 
planes contain a slight film of limonite but are not very numerous. 

A number of additional shafts have been put down on this farm to 
prove the value of this clay. The sections exposed in these shafts are 
as follows: 

SeeHons in ghafts on Murray farm, near Lyons. 

Vo. 1, on the banks of a branch of Davldioa Crack. 


Gray sandstone 2 

Blue fuller's earth 4 

Sand, loose 2} 

Ho. 8, about iOO feet a Utile cast of north from XTo. 1. 

Black soil 2 

Gray sandstone } 

Blue fuller's earth 10 

Lignite 2 

No. 8, about 100 feet a Utile west of north from Vo. 8. 


Overburden, black soil 2 

Red fuller's earth, probably weathered phase of bed below 3 

Blue fuller's earth 4 

Clay 6 


Vo. 4, about 800 east of No. S. 


Overburden g 

Gray fuller's earth 4 

Blue fuller's earth 8 


Digitized by 



Ho. 9, about 600 feet a Uttle east of loath from Vo. 1. 


Overburden 2 

Clay 4 

Blue f uUer's earth 8 


XTo. S, abovt MO feet wert of Ho. 5. 


Black 8oa 3 

White sandstone 7 

Fuller's earth 12 


The area covered by these prospect shafts is 40 acres. The fuUer's 
€)arth that is found in them is probably available, however, over 70 
or 80 acres of ground. 

The main line of the Gulf, Colorado & Santa Fe Railway crosses 
this farm, so that this deposit is very favorably situated with regard 
to transportation facilities. Any clay pits opened here could be 
readily drained without pumping. The conditions as regards labor 
and fuel are similar to those for other clays in the general vicinity of 

It is thought that this clay may be useful as a fuller's earth, but 
thus far tests to prove its value for this purpose have not been com- 
pleted. Burning tests show emphatically that this clay is not adapted 
for the manufacture of burned products. The results of these tests 
appear below. 

Btaning behavior and pkysical properties of clay on /. C, Murray farm^ S miles riorth of 
Lyons, Burleson County (No. 381), 

Description of raw clay Blue shale, medium, fine grained; grinds 


Molding behavior 1 Fuller's earth(?); laminates excessively. 

Drying behavior Warps and cracks; not possible to make 

draw trials. 
Drying shrinkage, per cent of wet length. .10.6. 
Remarks This clay is of absolutely no value as a 

material for manufacturing clay products. 

It was not tested for fuller's earth. 



On the Paul Taylor farm, H Tmles northwest of Somerville, Burleson 
County, occurs an extensive deposit of compact brown leaf-bearing 
shale that may be tentatively classed as fuUer's earth. The location 
is indicated by No. 383 on the map (PI. VI). 

This deposit occurs in the Jackson formation and lies directly on 
top of the gray sandstones which have been previously described as 

Digitized by 



overlying the clay at the Somerville fuller's earth plant. This clay 
is very well exposed on a branch of Yegua Creek, where the following 
section may be seen: 

Section on branch of Yegua Creek near Somerville. 


1. Brown clay soil, with specks and small particles of gravel 

(overburden) ^ 1.6 

2. Laminated brown shale, with seams of sand 1 inch thick 5. 2 

3. Compact, massive brown shale, with flakes of gypsum, etc., 

also carrying leaf impressions 13. 2 

No. 3 is the commercially valuable clay. The clay is finegrained, 
even textured, and of uniform chemical and physical composition 
over a large area. It breaks with a subconchoidal fracture; its 
hardness is between 2 and 3 on the Mohs scale. This bed dips half a 
degree to the east-southeast. 

M. M. Graves, of Somerville, has prospected this deposit by means 
of shafts and states that he has found this clay covering some 57 
acres of ground, beneath an overburden that will average 5 or 6 feet 
in thickness. The precise records of these shafts are unfortunately 
not available, and the shafts themselves were filled up soon after 
they were dug. 

This deposit is situated 500 yards west of the main line of the Gulf, 
Colorado & Santa Fe Railway, and can be easily reached with a spur. 
Facilities for the natural drainage of any clay pits that might be 
opened here are good. The conditions as regards labor, fuel, and 
water are similar to those for other clays in the general vicinity of 

Tests to determine the value of this clay for fuller's earth indicate, 
according to Mr. Graves, high bleaching and decolorizing power. 
The survey tests on samples collected by the writer are not yet 

The burning tests seem to indicate that this clay is not very well 
adapted for the manufacture of burned products. It cracks badly 
in drying and fuses at a comparatively low temperature. The diffi- 
culties might in part be corrected by the addition of sand, but it is 
questionable whether this would prove profitable in view of the great 
abundance of available brick clays in this State. The results of these 
burning tests appear below: 

Burning behavior and physical properties of day on Paul Taylor place^ 1\ miles north of 

Som^erville {No. S8S). 

Description of raw clay Fine-grained, medium-hard shale; tem- 
pered in wet pan(?). 

Molding behavior Very plastic; works well on machine. 

Drying behavior Warps and cracks badly. 

Drying shrinkage: 

Per cent of wet length 11. 4 

Per cent of wet volxime 34. 00 

Digitized by 



Burning ahrinkage, per cent of wet 

lengtii 6.3 

Total linear shrinkage, per cent of wet 

length 17.70 

Poroflity at cone . 010 per cent. . 28. 34 

.08 do.... 27.71 

06 do.... 26.06 

04 do.... 20.08 

02 do.... 16.50 

1 do....' 13.81 

3 do.... 12.49 

5 do.... 8.61 

7,9 Fused. 

Color after burning Bu£f; darkens at higher temperature. 

Hardness Steel hard from cone .08 to cone .5. 

Best burning temperature 1,230® C. 

Remarks Clay not well suited for clay products, 

owing to difficulty in drying and short 
vitrificatlan range. 


On Red Gully Creek, on the David Heirs League, 7^ miles north of 
Burton, Washington County, occurs a deposit of hard brown leaf- 
bearing shale wliich belongs to William Bauer, of Burton. The 
location is indicated by No. 394 on Plate VI. 

This deposit is similar in geologic relations to clay No. 383. 

The clay is nicely exposed in the canyon walls of Red Gully Creek. 
Half a mile north of the Texas Fuller's Earth Co.'s plant the following 
section is exposed in the bank of this creek: 

Section in bank of Red GvUy Creek 4 miles north of Burton. 


Gray sandstone 1 

Lignite or lignitic clay ) 

Brown shale 1 

Lignitic shale 1 

Hard brown shale J 

Brown clay i 

Lignitic shale 1 

Yellow or brown clay 1 

Hard brown leaf-bearing shale 10 


The leaf-bearing shale is compact, fine grained, of uniform chemical 
and physical composition, but excessively hard, the hardness being 
between 3 and 4 on the Mohs scale. The beds dip slightly to the 

Frank Graves, of Burton, has prospected this deposit and gives 
the following details concerning its extent and distribution as revealed 
by his drill holes: 

Digitized by 



Drill hole No. 1, about one-fourtli mile north of the Texas Fullers 
Earth Co.'s plant and about half a mile south of the exposure in Red 
Gully just described, showed 3 feet of stripping on top of 5 feet of the 
brown fuller's earth. Drill hole No. 2, about 200 feet N. 45'* E. from 
hole No. 1, showed 22 inches of overburden on top of 6 feet of brown 
fuller's earth. Hole No. 3, about 200 feet N. 45° E. from No. 2, 
showed 20 inches of overburden on top of 5 feet 3 inches of brown 
fuller's earth. Hole No. 4, about 200 feet N. 45° E. from No. 3, 
showed 20 inches of overburden overlying 5^ feet of brown fuller's 
earth. Hole No. 5, about 300 feet N. 45° E. of No. 4, showed 18 
inches of overburden on top of 6 feet of fuller's earth. Hole No. 6, 
100 yards distant from No. 5, contains no fuller's earth, being 
apparently beyond the northern limit of its outcrop. Only sand- 
stone appears in this drill hole. Hole No. 7, about 200 yards west of 
hole No. 1, showed 7 feet 10 inches of fuller's earth, overlain by 7 feet 
of overburden, of which the uppermost foot is sandstone. Prac- 
tically the same conditions were met in holes Nos. S and 9, distant 
300 and 600 feet, respectively, from hole No. 7 in a direction N. 10° W. 
No. 10, a shaft located about 300 feet N. 10° W. from No. 9, showed 
10 feet of hard brown fuller's earth (probably the same as the stratum 
described in the section on Red Gully) overlying 5 feet of fine white 
fuller's earth. Hole No. 11, about 600 feet N. 10° W. from the 
shaft (No. 10), showed 4 feet of overburden on top of 3 feet of reddish- 
brown fuller's earth, which in turn Ues on top of 5 feet of white 
fuller's earth. Hole No. 12, on the east side of Red Gully, about 1,200 
feet north of hole No. 4, showed a large quantity of fuller's earth, 
wliich was not penetrated. 

This entire tract covers 49 acres. It is probable that the drill holes 
above described have penetrated one or more beds of fuUer's earth, 
not all of which are stratigraphically continuous with the leaf-bearing 
bed in the section on Red Gully described on page 347. In any event, 
there is present here a considerable body of clay that will vary in 
thickness from 5 to 10 feet, covered with 2 to 5 feet of overburden. 
It is probable that the area described contains a number of clays 
that differ from one another, at least in chemical composition. 

This deposit is situated 7i miles north of Burton, the nearest rail- 
road point. For the present therefore tliis clay is not commercially 
available and could come on tlie market only in the event that a 
railroad should be built through this territory. 

Tests made by Frank Graves show that tliis clay possesses good 
bleaching power. 

The country here is cut into canyon-like hollows by the creeks and 
is veneered with a thin sheet of gravel and covered with post-oak 
timber. Facilities for the natural drainage of clay pits exist here. 
The conditions as regards possible suppUes of fuel, labor, and water 

Digitized by 



are similar to those indicated for the deposit of the Texas Fuller's 
Earth Co. 

It appears from the results of tlie burning tests that tliis clay is 
weU adapted for the manufacture of building brick, etc. The results 
of these tests follow: 

Burwmg behavior and phy$ieal properties of clay on Red Gully Creek, 7) miles north oj 

BwrUm {No. ,194). 

Description of raw clay Brown, medium fine grained ahale; grinds 


Molding behavior Fuller's earth(?); good working plasticity; 

rather sandy; works well on machine. 

Drying behavior Good. 

Drying shrinkage: 

Per cent of wet length 7.52 

Percent of wet volume 20.40 

Burning shrinkage, per cent of wet volume. 7. 6 
Total linear shrinkage, per cent of wet 

length 15.12 

Porosity at cone .010 per cent. . 42. 00 

.08 do.... 37.20 

.06 do 33.60 

.04 do.... 28.40 

.02 do.... 32.00 

1 do.... 25.30 

3 do.... 29.10 

5 do.... 19.80 

7 do.... 18.70 

9 Melting point not determined. 

Color after burning Fair buff. 

Hardness Steel hard at cone 5; stands well at cone 9. 

Best burning temperature 1,230^ C. 

Remarks This clay is favorable for tho manufacture 

of building bricks, etc. 


On the Burkhart land, on a branch of Turkey Creek, about 2 miles 
east of Ledbetter, m Washington County, occurs another deposit of 
brown shale or fuller's earth that is similar in general character and 
geologic relations to the clay of the Somerville Fuller's Earth Co. 
(p. 337). The location is indicated by No. 404 on tho map (PI. VI). 

This deposit is apparently stratigraphically continuous with the 
Somerville fuller's earth (No. 382) and, like that clay, is doubtless of 
lacustrine or palustrine origin, having been deposited in a lagoon or 
swamp adjacent to the shore in Jackson time. 

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On the creek the following exposure may be seen: 

Swiwn on bramA of Turkey Crteh, t mUu east ofLidbetUr, 

Hard giay aandstoiiei apparently the stndgraphic equivalent of 

the sandstone that overlies the clay at the Somerville fuller's Feet. 

earth plant; this sandstone b used locally for building 4-5 

Hill slope, covered with gravel and soil; beds not visible 35 

Yellow shale, exposed 2 

Hard brown shale 2 

Soft brown shale 5+ 


The soft brown shale is the apparently commercially valuable clay 
at this point. This clay is a compact, even-grained light-brown shale 
or fuller's earth of imiform physical and mineralogical composition 
over a considerable area. The beds dip slightly to the south. 

Regarding the extent of this deposit little is definitely known. 
However, there can be little doubt that this clay covers an extensive 
area in this section, for it was foimd in the shaft at the lignite mines 
2 miles west of the exposure described above. 

The overburden varies in places from 2 to 5 feet in thickness; at 
least it will be possible to locate an area of clay in this vicinity in 
which the overburden will not exceed 6 feet. This covering consists 
chiefly of Pleistocene gravel, which extensively veneers the surface 
in this vicinity, and clay. There is no great amount of rock. A con- 
siderable demand has been developed in this vicinity for the gravels 
for railroad ballast, and a great number of pits are operated and ship 
gravel for this purpose. Some of the land in this region commands 
as much as $30 an acre merely because it contains gravel. The over- 
burden therefore is not a hindrance to the working of these clay 
deposits, because it can be removed as a by-product and sold at a 

This gravel flat is covered with a heavy growth of post-oak timber, 
which is available as fuel. In addition, a considerable body of lignite 
occurs 50 to 60 feet beneath this clay. This lignite has been worked 
in times past at Ledbetter, and it is expected that operations on it 
will be resumed in the near future. Thi3 deposit is but a mile distant 
from the Austin branch of the Houston & Texas Central Railroad and 
could be readily reached with a spur. Drainage of clay pits could 
probably be provided by a natural system, though it may be neces- 
sary to resort to pumps in the course of time. For labor, negroes 
and Mexicans can be hired at prices ranging from $1 to SI. 50 a day. 
Water can be had in wells and from impoimding reservoirs. 

The tests to determine the value of this clay as a fuller's earth 
have not been completed. Burning tests seem to show that it is not 
adapted to the manufacture of burned products. It cracks badly in 

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drying, fuses easily and rapidly, and burns to an unsatisfaotor7 color. 
The results of these tests appear below: 

Svminq behavior and physical properties of clay on Bvrlhart lands near LedbeUer 

(No. 404). 

Deecription of raw clay Hard brown ahale; grinds easily. 

Molding behavior Very plastic and sticky; works well on 


Drying behavior Cracks; made over by hand. No shrink* 

age measurements. 

Porosity at cone .010 per cent. . 32. 60 

.08 do 30.50 

.06 do 26.40 

.04 25.30 

.02 do 18.90 

1 do.... 12.70 

3 do.... 25.60 

5 do.... 1.3 

5, 7 Fusing. 

Color after burning Bui! at lower temperature; a poor red at 


Hardness Vesicular at cone 3; fused at cone 5. 

Best burning temperature 1,150^ C. 

Remarks Unsatisfactory in drying, vitrifying range, 

and color. 

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In addition to the papers named below, some of the publications 
listed under the heading ''Cement and concrete materials" contain 
references to clays. Certain of the geologic folios also contain refer- 
ences to clays, fuller's earth, etc. 

These publications, except those to which a price is affixed, can be 
obtained free by applying to the Director, United States Geological 
Survey, Washington, D. C. The priced publications may be pur- 
chased from the Superintendent of Documents, Groyemment Printing 
Office, Washington, D. C. 

Alden, W. C. Fuller's earth and brick clays near Clinton, Mass. In Bulletin 430, 
pp. 402-404. 1910. 

Ashley, 6. H. Notes on clays and shales in central Pennsylvania. In Bulletin 
285, pp. 442-444. 1906. 

Ashley, H. E. The colloid matter of clay and its measurement. Bulletin 3SS. 
C5 pp. 1909. 

Bastin, E. S. Clays of the Penobscot Bay region, Maine. In Bulletin 285, pp. 
428-431. 1906. 

Branner, J. C. Bibliography of clays and the ceramic arts. Bulletin 143. 114 
pp. 1896. 15c. 

The clays of Arkansas. Bulletin 361. 247 pp. 1908. 

Burrs, Charles. Clays of the Birmingham district, Alabama. In Bulletin 315, 
pp. 291-295. 1907. 50c. 

Crtoer, A. F. Clays of western Kentucky and Tennessee. In Bulletin 285, pp. 
417-427. 1906. 

Darton, N. H. Geology and water resources of the northern portion of the BUck 
Hills and adjoining regions in South Dakota and Wyoming. Professional Paper 65. 
106 pp. 1909. 

Darton, N. H., and Siebenthal, C. E. Geology and mineral ^sources of the 
Laramie Basin, Wyoming; a preliminary report. Bulletin 364. 81 pp. 1909. 

Eckel, C. E. Stoneware and brick clays of western Tennessee and northwestern 
Mississippi. In Bulletin 213, pp. 382-^91. 1903. 25c. 

Clays of Garland County, Ark. In Bulletin 285, pp. 407-411. 1906. 

Fennbman, N. M. Clay resources of the St. Louis district, Missouri. In Bulletin 
315, pp. 315-521. 1907. 50c. 

Fisher, C. A. The bentonite deposits of Wyeming. In Bulletin 260, pp. 559-563. 
1905. 40c. 

Clays in the Kootenai formation near Belt, Mont. In Bulletin 340, pp. 

417-423. 1908. 

Fuller, M. L. Clays of Cape Cod, Massachusetts. In Bulletin 285, pp. 432-441. 

Landbs, Henry. The clay deposits of Washington. In Bulletin 260, pp. 550^558. 
1905. 40c. 

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Lines, E. F. Clayp and ahales of the Clarion quadrangle, Clarion County, Pa. In 
Bulletin 315, pp. 33&-343. 1907. 50c. 

Matson, G. C. Notes on the clays of Florida. In Bulletin 380, pp. 346-366. 1909. 

MiDDLBTOK, Jefferson. Clay- working industries. In Mineral Resources U. S, 
for 1909, pt. 2, pp. 453-517. 1911. » 

Phalbn, W. C. Clay resources of northeastern Kentucky. In Bulletin 285, pp. 
412-416. 1906. 

Economic geology of the Kenova quadrangle, Kentucky, Ohio, and West 

Virginia. In Bulletin 349, pp. 112-122. 1908. 

Phalen, W. C, and Martin, Lawrence. Mineral resources of Johnstown, Pa., 
and vicinity. Bulletin 447. 140 pp. 1911. 

Clays and shales of southwestern Cambria County, Pa. In Bulletin 

315, pp. 344^54. 1907. 50c. 

Porter, J. T. Properties and tests of fuller's earth. In Bulletin 315, pp. 268-290. 
1907. 50c. 

Ries, H. Technology of the clay industry. In Sixteenth Ann. Rept., pt. 4, pp. 
523-575. 1896. $1.20. 

The pottery industry of the United States. In Seventeenth Ann. Rept., 

pt. 3, pp. 842-880. 1896. 

The clays of the United States east of the Mississippi River. Professional 

Paper 11. 298 pp. 1903. 40c. 

ScHRADBR, F. C, and Haworth, E. Clay industries of the Independence quad- 
rangle, KansM. In Bulletin 260, pp. 546-549. 1905. 40c. 

Shalkr, M. K., and Gardner, J. H. Clay deposits of the western part of the 
Durango-Gallup coal field of Colorado and New Mexico. In Bulletin 315, pp. 296- 
302. 1907. 50c. 

Shaler, N. S., Woodworth, J. B., and Marbut, C. F. Ite glacial brick clays 
of Rhode Island and southeastern Massachusetts. In Seventeenth Ann. Rept., 
pt. 1, pp. 957-1004. 1896. 

SiEBENTHAL, C. E. Beutonite of the Laramie Basin, Wyoming. In Bulletin 285, 
pp. 445^47. 1906. 

Stose, G. W. White clays of South Mountain, Pennsylvaina. In Bulletin 315, 
pp. 322-334. 1907. 50c. 

Van Horn, F. B. Fuller's earth. In Mineral Resources U. S. for 1907, pp. 731-784, 
pt. 2. 1908. $1.00. 

Vauohan, T. W. Fuller's earth of southwestern Georgia and Florida. In Mineral 
Resources U. S. for 1901, pp. 922-934. 1902. 50c. 

Fuller's earth deposits of Florida and Georgia. In Bulletin 213, pp. 392-399. 

1903. 25c. 

Veatch, 0. Kaolins and fire clays of central Georgia. In Bulletin 315, i>p. 303- 
314. 1907. 50c. 

WooLSEY, L. H. Clays of the Ohio Valley in Pennsylvania. In Bulletin 225, 
pp. 463-480. 1904. 35c. 

1 Pievioas volumes of the Minwid Besourocs of Unitwi States oontala «1ftapters <ieTOtcd to etoy and tiM 

clay-working Industries of the United States. 

94174"*— Bull. 470—11 23 

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By Ernest F. Burchard. 


In the summer of 1910 the writer, wliile investigating a number 
of deposits of gypsum of possible commercial value in the Western 
States, made a very hasty reconnaissance of the gypsum deposits of 
Eagle County, Colo. Of the many areas visited that of Eagle County 
seems the most worthy of special mention on account of the large 
quantity of gypsum rock that is available along the main line of the 
Denver & Rio Grande Railroad. (See fig. 44.) The local descrip- 
tions given below are a transcript of field notes and are supplemented 
by a few analyses made in the laboratories of the United States 
Geological Survey; they are intended merely to call attention to the 
deposits rather than to give a complete description of the area. As 
the Survey has no facilities for making practical tests of the quality 
of the gypsmn, this feature necessarily is the least certain of all the 
facts under consideration. Judged by appearances these gypsum 
deposits are as promising as many that are worked for making plasters 
in other parts of the West, and most of them are far more easily 

Before the development of any deposit of gypsum is imdertaken 
very careful investigations should be made of the quality of the 
material and of the quantity available. Chemical analyses of a few 
selected samples are not sufficiently reliable, nor are chemical analyses 
of large quantities of representative material to be relied upon 
implicitly. Large quantities of the material should be calcined and 
made into plaster, and the characteristics of the plaster should be 
determined before any money is spent in clearing ground for a mill. 


No geologic maps or detailed studies of the stratigraphy within 

Eagle County have been made by the United States Geological 

Survey. Hayden, Peale, and others studied this region in 1873 and 

1874 and published the results of their work in volumes 7 and 8 of 


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the reports and in the atlas of topographic and geologic maps issued 
by the Geological and Geographical Surveys of the Territories. Mr. 
E. M. Kindle, of the United States Geological Survey, has recently 
made paleontologic studies in the canyon of Grand River 4 or 5 miles 
below the Ei^le County line and has kindly examined some fossils 
collected by the writer from Cottonwood Creek, thereby determining 
\vith certainty the age of some limestone beds that lie not far below 
the gypsum-bearing formation. 

Eagle River, which enters the county near its southeast comer and 
flows northwest and west to its confluence with Grand River at 

TtouBS 44.~Index map of Colorado, showing looatlon of Eagle County. 

Dotsero, in the middle of the county, is the major drainage feature 
of the county. Grand River, which flows across the northwest comer 
of the county, is geographically the next feature of importance. The 
surface is in general rough, with a maximum relief of over 6,000 feet 
between the level of Eagle River, which is about 7,000 feet above 
sea level in the western part of the county, and the summit of Mount 
Powell, which has an altitude of more than 13,000 feet. There are 
three shallow canyons on Eagle River; the upper is above RedcliflF, 
the second is near Wolcott, and the lower is below the mouth of Gyp- 
sum Creek. Between these canyons are comparatively broad vallejra 
occupied by flood-plain deposits, and the valleys of Gypsum Creek, 
Brush Creek. South Eagle River, and Beaver Creek are of similar 

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nature and are wide enough in thjeir lower reaches for agricultural 
purposes. Eagle River throughout most of its course in the county 
and Grand River below the mouth of Ea^e River flow along the axis 
of a syncUne composed of sedimentary rocks of Qrdovician, Silurian, 
Devonian, Carboniferous, Triassic, Jurassic, Oetaceous, and Ter- 
tiary age, the oldest of these sediments resting on gneksoid and 
granitic crystalline rocks. Tliis synclinal trough is slightly basin- 
shaped, with the deepest depression in the vicinity of Wolcott, where 
the Cretaceous and Tertiary beds cap the surfaces adjacent to the 
river. In a few places there are remnants of basalt flows on the 
higher levels overlying the Tertiary rocks. 

The approximate thickness of the systems of sedimentary rocks 
in northwestern Colorado is as shown below, according to Peale.* 
The Cretaceous and Tertiary rocks do not reach such great thick- 
nesses as far east as Eagle County. 

Sedimentary fornuUions in Eagle County , Colo. 


Tertiary 7 , 000-8, 000 

Oretaceoufl 4, OWM, 700 

Juraaaic 400- 900 

Triaasic 1,000-1,500 

CarboniferouB (Miseissippian (?), Pennsylvanian, and Per- 
mian) 4, 000 

Devonian 1,000-1,500 

Silurian and Ordovician 820 

Oambrian (?). 

The gypsum beds occur in the upper part of the Carboniferous 
system, probably in the Permian series, and these are the only rocks 
that need to be considered here. The Hayden Survey mapped the 
Carboniferous rocks as Lower, ACddle, and Upper. The Lower divi- 
sion probably corresponds roughly to the Devonian and Mississippian 
rocks, and the Middle and Upper divisions to the Pennsylvanian and 
Permian series. The thickness of the upper division of the Car- 
boniferous, or the Permian, is about 1,500 feet. A section measured 
by Peale ' on Eagle Biver is as follows: 

Section o/'^PermO'Carhoniferoue" rocks on Eagle River ^ Colo, 

Sfaaly aandatone, pink, brown, and gray, with iuterlami- Fq«I. 

nated bedaof blue Umeatone, about 200 

Shaly aandstone and limestone, alternating colors pink, 
brown, gray, yellow, white, cream, and blackish. These 
beds are best shown on the north side of the river. They 
incline generally about 60^. In some places they are 
inclined past the vertical in the upper portion. Thick- 
ness about 500 

> Peale, A. C, U. S. Oeol. and Qeo|{. Survey Terr., vol. 8, 1S74, pp. 110-141. 
• Idem, 

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Gypsifnous shale and sandstone. The gypeum occurs in 
great quantity « and it is rather impure. The sandstone is 
laminated and generally of a pink or red color. Apparent Feet, 

thickness of outcrop 50(>- 800 

1, 20O<l, 900 

The thickness of the gypsiferous series appeared to the writer to 
be greater rather than less than the maximum of 800 feet given 
above. The predominant color of the gypsiferous shale is gray, and 
that of the gypsum beds is an ashy gray which can be recognized 
for many miles. As noted in the local descriptions, the inclination 
of the gypsum beds is in most places rather steep. Peale considers 
that the gypsiferous series is probably tipped up with the overiying 
beds^ and makes the following statement: ''It is difhcult here to 
reduce the [gypsiferous] strata to any order. Their softness has 
caused them to yield readily to eroding influences, and they have 
vreatheted into low hiUs in which they are for the most part con- 
cealed. There are one or two folds in them of some extent, * * * 
Besides, however, theie are numerous minor foldings which would 
require more time than we could give to reduce them to any system. " ' 
Peal© considers that the gypsiferous beds on Eagle River and on 
Fryingpan Creek, as well as those along.Grand River above the mouth 
of the Eagle River, belong to the same series. 

The gypsum masses appear to be lenses of various dimensions 
interbedded with shale and to occur at no definite horizons. The 
lenses range in thickness from a few feet up to 200 feet or more. 
They generally contain shale bands or beds mixed with the gypsum, 
and the gypsum probably contains more or less impurity, chiefly 
in the form of lime, alumina, and silica. The gypsum masses have 
resisted weathering slightly better than the inclosing beds of shale 
and in many places they project as ledges or faint ridges, but the 
gypsum also weathers rapidly and is inclined to slump down in 
large masses and mix with the shale, so that it is difficult to ascertain 
the true thickness of any deposit of gypsum, or to determine what 
its condition in the imweathered or rock form may be. 


One-half to three-fourths of a mile soutlieast of Gypsum station 
gypsimi outcrops in a hill on the west side of the Gypsmn Creek 
valley. (See fig. 46.) The outcrop strikes north or slightly west 
of north, and the dip is generally rather steep toward the east, 
although in places the beds stand nearly vertical or dip steeply 
toward the west. The apparent area of outcrop of the bed may 
have been increased through overturning and sUding of masses down 
the hill. The outcrop occurs on the axis and east flank of a low 
ridge, which is cut in two by a gully, giving good exposures of the 

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edges of the gypsum beds. The material is massive rock gypsum, 
rather soft on the exposed edges on account of weathering, so that 
the material has crumbled to a powder in many places. The color 
is generally grayish, but where unweathered the rock is lighter 
than the weathered material. Both the rock gypsum and the soft 
weathered material effervesce with hydrochloric acid, the powder 
effervescing the more briskly. The thickness of the bed appears 
to be at least 150 feet here; the length of the exposure is about 
1,500 feet and the height ranges from 25 to 150 feet. About 20 
carloads of gypsum are reported to have been quarried here and 

-f Gypsum srees 

FiGUBB 45.~Map showing a'eas of gypsum in Eagle County, Colo. (From General Land OlBoe map 

of Colorado, 1910.) 

shipped to Portland, Colo., in 1906 and 1907, for use in the manu- 
facture of Portland cement. The old quarry shows a face about 
100 feet high and 150 feet wide at the base of a small spur. There 
is very little overburden, except a cover of impure gypsite 1 foot 
to 10 feet or more in thickness. An analysis furnished by Mr. A. 
KoUquist, of Gypsum, Colo., showed the following constituents: 
SiUca, 0.2 per cent; ferric oxide and alumina, 0.1 per cent; calcium 
sulphate, 78.8 per cent; water, 20.9 per cent. (See also analysis 
No. 1, p. 365.) 

About 3 miles south of Gypsum station, on the east side of the 
Gypsum Creek valley, some gypsum-bearing beds outcrop. The 

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fonnatlon is composed of greenish-gray shale. The beds strike 
about N. 35** E. and dip generally toward the southeast at moderate 
angles. There are no extensive single beds of gypsum here. On 
the low hill at the east of the road there are two small outcrops 
separated by shale. Some of the gypsum thus showing has probably 
had its outcrop enlarged by slumping down and spreading out. 
The haul to the railroad is rather too long for immediate develop- 
ment, although it is down a gentle grade on good wagon road. 

In the north bluffs of the Cottonwood Creek valley are exposed 
several gypsum beds beginning at a point 3 miles above the mouth 
of the creek and extending for more than 3 miles upstream. This 
locality is about 8 miles from Gypsum station. The general strike 
is from northwest to southeast, and the dip is about 15** NE. The 
beds lie generally high in the bluffs or at the very top. Much of 
the associated rock appears to be a hard gypseous material with 
interbedded layers of black shale. (See analysis No. 3, p. 365.) 
Three gypsum beds were noted in this locality. The dip of the 
beds carries their plane too high to intersect the bluffs on the opposite 
side of the creek. The lower part of the valley of Cottonwood Creek 
becomes a canyon between walls of hard, fractured, blue limestone, 
which weathers brown on the surface. Fossils collected from this 
limestone have been determined by E. M. Eucndle to be of Upper 
Devonian age, belonging to the Ouray fauna, and the rock resembles 
most closely the limestone which represents the lower part of the 
Ouray limestone near Glenwood Springs. The possibility of the 
commercial development of these beds is very doubtful under present 
conditions, for it would be practically impossible to build a railroad 
or tramway up Cottonwood Creek canyon. Haulage over the 
divide to Gypsum station is also impracticable under present con- 
ditions, as there is so much gypsum accessible along Gypsum Creek. 
It is reported that in the canyon of Gypsum Creek in T. 7 S., R. 84 W., 
about 15 miles southeast of Gypsum, gypsum is exposed for about 
4 miles. These deposits were not visited, as they are so remote 
and inaccessible as to be of no commercial importance for many 
years, if at all. Over the divide, on the north side of Fryingpan 
Creek, are important deposits on the line of the Colorado Midland 
Railroad, which are described on page 363. 

On the north side of Eagle River, 2^ miles above Gypsum, a 
number of lenses of gypsum are exposed in the river bluffs. The 
general strike of these beds is about N. 65° W., and they have a steep 
northeastward dip. The beds are much bent by folding and slumping 
over. The beds are inclosed in calcareous to sandy shale, and the 
exposure of one of the largest masses shows a total thickness of 
about 140 feet across the beds, as shown on the next page. 

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Section of gypsum beds and associaUd 8tr€Ua jS^ miles east of Gypsum. 


Gypsum 25 

Clay shale 10 

Gypsum. .% 25 

Clayshftle 15 

Gypsum 20 

Clayskale 25 

Gypsum 20 

The heigbtt of this biuif i» about 250 feet. The gypsum is dark* 
gray shidy material. Near the top of the series the beds are extremely 
hard, but lower down the material is in many places v^ry soft and 
earthy. When treated with hydrochloric acid it gives a tmnt offer- 
yescence. The gypsum contains much seleno^ie in m<e<fium-sized crys- 
tals, and some dark shaly bands also contain selenite crystals. The 
three partings of clay shale are calcareous. There is very Uttle over- 
burden on top of .this bluff, as the beds are exposed akmg the strike,^ 
bwt a heavy talus of gypseous clay lies in front of the face of the expo- 
surC) extending to a height of 75 to 150 feet above the flood plain of 
Eagle River. The deposits are about three^fourths of a mile from the 
Denver & Rio Graside Railroad, on the opposite side of the river. 
An analysis (No. 2, p. 365) of a small sample of rock gypsum from this 
locality showed that the sample was anhydrite. It 19 not probable 
that anhydrite constitutes the whole or even a la#ge part of this 
deposit; b«it the fact that it is present is significant and emphasizes 
the necessity f«r thorough sampling. 

Northward from Gypsum station, along an abandoned wagon road 
th«t leads from Eagle River to Grand River, gypsum shows in large 
masses, outcropping in the hillsides, in the gullies, and on mountain 
tops for about 4 miles back from Eagle River. All the surface mate- 
rial is so weathered and washed down that it is nearly impossible to 
distinguish the limits of the gypsum beds within 15 to 25 feet of accu- 
racy, or to determine their exact dip and strike. In general the strike 
seems to be between N. 5** W. and N. 45** W., although in places the 
beds seem to have a more westerly trend . The material is locally very 
selenitic. At the top of one large bluff, about H miles from Eagle 
River, large blocks of selenite, from which plates 15 inches square 
might be split, were noted. Large masses of gypsmn have slumped 
down from the outcrops and appear thus to be in places at levels 
which are lower than the actual position of the beds. The soft, 
weathered gypsum mixes so readily with the soft calcareous shale 
which incloses it that it is almost impossible to ascertain from surface 
appearances just what the true relation of the mass of gypsum may 
be imless it can be traced .for a long distance in the direction of the 
strike. It is therefore necessary to prospect these beds on a rather 
large scale in order to determine their true thickness and extent. In 

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places beds seem to dip in opposite directions on opposite sides of a 
divide, but the dips appear mainly to be toward the northeast, and 
range from 20^ up to rertical. The thickness of the more important 
beds of gypsum, so far as it could be determined, ranges from 100 to 
200 feet, and many single beds may be traced for one-fourth to three- 
fourths of a mile. There are at least three beds of importance, and 
there may be several more. The rocks include many thin beds of 
gypsum and some beds of dark gypsiferous shale. The strip of land 
3 or 4 miles wide, inchiding the divide between the Eagle River and 
Grand Biver basins, appears to be composed of a limy shale and thin 
limestone, carrying ftttle or no gypsum. It is covered by a growth 
of cedar and i»fion, whieh do not flouridi on gypsiferous soils. At 
the summit are remnants of a flow of hard dark-brown vesicular basalt. 
On the slope toward Grand River gypsum is present in abtuidance. 
Between the ravines locally known as Trail Qulch and Sheep Gulch 
enormous masses of it appear m all attitudes in the bhiffs, capping 
them for kmg stretches; in other places outcropping on the flanks and 
dipping into the hills; ako lying in masses on the flanks and near the 
bases of the hills, evidently the result of landslides. In Trail Gulch 
large deposits occur within 1^ miles of Grand River. In Sheep Gulch 
the gypscun is not so abundant and in places has a dark cok>r and 
carries interbedded black carboniferous shaly material. (See analysis 
No. 4, p. 365.) 

None of the deposits on the slope toward Grand River will be com* 
mercially important until a railroad is built down Grand River from 
McCoy to Dotsero, but it is reported that two surveys have been made 
through tbis area and that a line is a possibility in the future. It 
would connect the Denver, Northwestern & Pacific Railway with the 
Denver & Rio Grande Railroad. In working such deposits as these 
cable tramways might be teed, and such a method of transporting 
the material would be almost necessary, for track tramways might be 
washed out by high water in the gulches after heavy rains. 

Three mdles southwest of Eagle, on the south side of the Eagle 
River valley, one-eighth of a mile from the Denver & Rio Grande Rail- 
road, are several exposures of gypsum in the bluffs. The beds stand 
nearly vertical, strike about N. 70^ W., and are inclosed in shale. The 
gypsum is grayish to white, with much soft, decomposed material on 
the surface and talus slopes. One of the most promising exposures 
has been located as a placer claim by persons living at Redcliff , Colo, 
The bed is 80 to 100 feet thick, with a face 30 to 100 feet high, and is 
exposed about 550 feet on the strike. There is a large supply of gyp- 
sum in this locality, several more beds having been noted in the hills 
between this point and the village of Eagle. Altogether the g}'psum- 
bearing formation is exposed for about li miles between Eagle and 
Gypsum. (See analysis No. 5, p. 366.) 

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At Avon; in the bluff at the junction of Eagle River and Beaver 
Creek, is a lai^e exposure of gypsum. The beds strike about N. 60° E. 
and dip at a moderate angle toward the northwest. The rock under- 
lying these beds is shale containing chert. There are two beds here, 
the lower one being about 130 feet thick and the upper one 50 to 75 
feet thick; they are separated by 40 to 50 feet of day, calcareous 
shale, and shaly limestone. The lower bed is mainly light-grayish 
rock gypsum of a subcrystalline texture where unweathered. It 
contains some small, hard dark masses of impure gypsum. All the 
material is highly calcareous. The lower two-thirds of the upper bed 
is largely crystalline selenite in aggregates of crystalline masses one- 
half inch to 3 inches long. The exposure of these gypsum beds 
extends for at least one-fourth mile along the bluff of Beaver Creek. 
To quarry the gypsum it would be necessary to remove in places 40 
to 50 feet of clay and calcareous shale or shaly argillaceous limestone 
where it projects beyond the upper bed. It is reported that claims 
have been filed by residents of Avon but that there is considerable 
gypsum remaining on Government land. The base of the gypsum 
lies about 350 feet above the level of the valley. A cable tramway 
about 1,500 feet long would reach a mill site near the railroad. A 
mill could be built on the hillside below the gypsum outcrop, but to 
connect it with the railroad a spur and a bridge over Eagle River would 
be necessary. 

Above Avon, on the southwest side of the Eagle River valley, witiiin 
2 miles there are 10 or 12 outcrops of gypsum masses, which are not 
80 well exposed, however, as the one at Avon. There «are probably 
not so many distinct beds of gypsum as there are outcrops of this 
material. Most of them are near the base of the bluff and many of 
them probably represent masses that have slumped down from a con- 
cealed bed at higher levels. About one-fourth mile southeast of the 
Beaver Creek exposure a bed shows at the top of a high point, and 
from the stratigniphic relations it is evidently a higher bed than the 
one at Beaver Creek. It is evidently of about the same thickness as 
the one described, and both of them may be traced for a mile or so 
southeast by outcrops or bare spots showing decomposed gypsum at 
levels corresponding with the relative positions of these beds. The 
most favorable place, however, for a mill in connection with a laige 
workable deposit of gypsum in this locaUty is near the mouth of 
Beaver Creek at Avon. There is apparently a suj£cient flow of water 
in Eagle River to furnish water power for a mill, unless more water is 
taken for irrigation. 

From Avon toward Edwards several more outcrops of gypsum show 
on the south side of the Eagle Valley. One that is well exposed is 
directly opposite Edwards, between one-half and three-quarters of a 
mile from the Denver & Rio Grande Railroad. About 1^ miles below 

Digitized by 



Edwards, gypsiun beds show in places for a mile in the west bluffs of 
South Eagle River, and gypsum-bearing rocks are present to a point 
in the valley about 2 miles below Edwards. The dip in this locality 
is generally toward the west, and the red formations of the Triassic 
overlying the gypsum-bearing series appear with westerly dips beyond 
this point, so that no more gypsum beds show toward thd west imtil 
the vicinity of Eagle is reached. 

Altogether the outcrop of gypsum-bearing rocks along Eagle River 
in this vicinity extends at least 7^ miles. In places the beds have 
been repeated by folding and by faulting. 

Over the divide south of the Gypsum Creek drainage basin, at the 
extreme edge of Eagle C!ounty, on the north side of Fryingpan Creek, 
at Ruedi, the Roaring Fork Plaster Co. is developing the only deposit 
^^ gypsum that is worked in the county. Ruedi is on the line of the 
Colorado Midland Railroad, which serves a somewhat different trade 
territory from that traversed by the Denver & Rio Grande Railroad, 
therefore the probabilities of strong competition between mills on the 
two roads are not great. The gypsum occurs in a mountainous mass 
of sediments which strike N. W W. to N. 25'' W. and dip from 30'' to 
W SW. As exposed in the quarry the gypsum beds are generally 
thick and are jointed and fractured. Shale and limestone are inter^ 
bedded in the formation above the quarry, but prospect openings at 
short intervals for half a mile from the quarry back to the summit of 
the mountain show that a very large proportion of the rock is gypsum. 
The summit of the ridge lies at least 1,400 feet above the valley level, 
and parallel to the valley the gypsum has been traced for at least a 
mile. On the south side of the valley, in Pitkin County, two small 
prospects show impure gypsum, but the material does not seem to be 
abundant in this direction. The gypsum as quarried is a light to dark-< 
gray and white rock gypsum, some of which is massive. It is mostly 
rather fine grained and hard. It contains some very hard streaks and 
pockets of dark material that seem to be mainly gypsum, and also 
some concretions of shale. In a few places clay seams have developed 
along joint planes that have been enlarged by solution. Faint traces 
of sulphur show on the surface of some of the darker beds in the 
quarry. The dark color has been thought possibly to be due to car- 
bonaceous residue. An analysis of this gypsum is given on page 365 
(No. 6). 

The quarry openings are on the east and west sides of a small gully, 
and the floor is on a level with the top of the mill. The faces of the 
two openings are about 100 feet wide and 80 feet high. The rock is 
blasted down with both black powder and dynamite, and it is neces- 
sary to reshoot the large blocks of gypsum. The stripping of soil 
and soft gypsum, which ranges from a few inches to 7 or 8 feet in 
thickness, is shoveled down into the quarry, carried out by cars, and 

Digitized by 



dumped at one side ol the traok. The gypsum is moved from the 
quftny to the mill in steri tram cars, which are let down an incline 
by cable. A train of two loaded cars hauls up two empties. The 
ci^acity of the ears is about 2,200 pounds each. From 65 to 70 tons 
of rock is quarried a day under normal conditions by ax men. For 
the best white-coat finish and plaster of Palis the rock is selected by 
hand. The dark and hard material is rejected and some of it must 
be culled out by hand. The cars are dumped sidewise ifito the rock 
bin at the mill. The rock is first passed through an Ehrsham jaw 
crusher and a rotary grinder and is carried by screw conveyor and 
elevator to three cylindrical steri storage bins, having A capacity of 
about 30 tons each. Fi:om these bins the material is fed to three raw- 
grinding burr milk. From the burrs the ground material ia conveyed 
by cars and elevators either direct to the kettles or to a storage bin 
for raw-ground materiiJ. From this bin the material may be drawn 
off and devated to the kettles. There are two 10-foot kettles having 
a capacity of 15 tons each. Two charges are run daily, makmg the 
total capacity of the mill 60 torn in nine hours, but the full capacity 
is seldom reached. The kettles are fired with so^alled lump coal 
from Cardiff, Colo., and pea coal is used for the boilers. The calcined 
material is drawn from the base of the kettles into adjoining hot pits 
built of local red sandstone. Screw conveyors 'and steel elevators 
convey the plaster from the hot pits to an inclined shaking screen. 
The fines go direct to tlie stock bins, and the ovetrs go to the regrinding 
bin. From the regrinding bin the material is moved by a screw con- 
veyor and chute to a regrinding burr mill. This mill discharges its 
product into an elevator that carries the material to a screw con- 
veyor leading to the steel stock bins, which have separate com- 
partments for wall plaster, molding plaster, and plaster of Paris. 
From tlie stock bins screw conveyors and elevators move the material 
to mixing bins. These bins supply the mixing hopper with plaster 
by a bottom feed. The operative who runs the mixer adds to the 
plaster definite quantities of retarder, hair, wood fiber, etc., as the 
order may demand. The mixing machine stirs the mat^al by means 
of paddles and allows it to pass downward into a compartment, from 
which it is fed directly into sacks. Two mixing machines are installed, 
although only one is generally used. The accessories in the mill are 
a wood-fiber macliine and a hair picker. Quaking aspen and cotton- 
wood, both local woods, are made into fiber. 

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The following analyses of gypsum from Eagle County were made 
by John G. Fairchild, of the United States Geological Survey, in 
March, 1911: 

Analyses of gypsum from Eagle County , Colo. 


















\ ia42 




} 2.29 




3a 74 

4a 40 










Hio..........;.. ;:....:::..:;:.:.:. :..::: 

2a ao 

OrgtBxilc riAtter 


1. Hall a mile flociUi of Gypsum, Colo. 

2. Two and one-half miles east of Qypsum, Colo. Nearly aobydrlte. 

3. Cottonwood Creek, 6 miles west-eouthwest of Gypsum, Colo. 

4. Eight mllesnortli of Qypsum, Colo. 

5. Eagle, Colo. 
0. Roedl, Colo. 

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The more important publications of the United States Geological 
Survey on gypsum and plasters are included in the following list. 
These publications, except those to which a price is aflSxed, can be 
obtained free by applying to the Director, United States Geological 
Survey, Washington, D. C. The priced publications may be pur- 
chased from the Superintendent of Documents, Government Printing 
Office, Washington, D. C. 

Adams, G. I., and others. Gypeum deposits of the United States. Bulletin 223. 
123 pp. 1904. 25c. 
BouTWBLL^ J. M. Rock gypsum at Nephi, Utah. In Bulletin 225, pp. 48S-487. 

1904. S5c. 

BuBCHARD, £. F. Gypsum and gypsum products. In Mineral Resources U. S. for 
1909, pt. 2, pp. 63^-647. 1911. 

Darton, N. H., and Siebenthal, 0. E. Geology and mineral resources of the 
Laramie Basin, Wyoming, a preliminary report. Bulletin 364. 81 pp. 1909. 

Eckel, E. C. Gypsum and gypsum products. In Mineral Resources U. S. for 

1905, pp. 1105-1115. 1906. $1. 

Harder, E. G. The gypsum deposits of the Palen Mountains, Riverside County, 
Cal. In Bulletin 430, pp. 407-416. 1910. 

Hess, F. L. A reconnaissance of the gypsum deposits of California. Bulletin 413. 
37 pp. 1910. 

Gypsum deposits near Cane Springs, Eem County, California. In Bulletin 

430, pp. 417-418. 1910. 

Richardson, G. B. Salt, gypsum, and i>etroleum in trans-Pecoe Texas. In Bul- 
letin 260, pp. 573-585. 1905. 40c. 

Shaler, M. K. Gypsum in northwestern New Mexico. In Bidletln 315, pp. 260- 
265. 1907. 50c. 

Siebenthal, C. E. Gypsimi of the Uncompahgre region, Colorado. In Bulletin 
285, pp. 401-403. 1906. 60c. 

G3rpsum deposits of the Laramie district, Wyoming. In Bulletin 285, 

pp. 404-405. 1906. 60c. 


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In addition to the papers listed below, which deal principally with 
fiznei magnesite; etc., further reference on limestones will be found 
in the lists given under the heads '^Cement" and Building stone.'' 
13iese publications, except the one to which a price is affixed, can be 
obtained free by applying to the Director, United States Geological 
Survey, Washington, D. C. The priced pubhcation may be pur- 
chased from the Superintendent of Documents, Gk)Yemment Print* 
ing Office, Washington, D. C. 

Basten, E. S. The lime industry of Enox County, Me. In Bulletin 285, pp. 
39&-100. 1906. 60c. 

BxmcHARD, £. F., Butts, Charles, and Eckbl, E. C. Iron ores, fuels, and fluxes 
of the Birmingham district, Alabama. Bulletin 400. 204 pp. 1910. 

BxmoHABD, E. F. Lime. In Mineral Resources TJ. S. for 1909, pt. 2, pp. 543-555. 

Butts, Charles. Limestone and dolomite in the Birmingham district, Alabama. 
In Bulletin 315, pp. 247-255. 1907. 

Calkins, F. C, and MacDonald, D. F. A geologic reconnaissance in northern 
Idaho and northwestern Montana. Bulletin 384. 112 pp. 1909. 

Hess, F. L. Some magnesite deposits of California. In Bulletin 285, pp. 385-392. 
1906. 60c. 

The magnesite deposits of California. Bulletin 355. 67 pp. 1908. 

Bibs, H. The limestone quarries of eastern New York, western Vermont, Massa- 
chusetts, and Connecticut. In Seventeenth Ann. Rept., pt. 3, pp. 795-811. 1896. 

Yale, C. G. Magnesite. In Mineral Kesources U. S. for 1909, pt. 2, pp. 841-843. 


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The list below includes the important publicatioDs of the United 
States Geological Survey on glass sand and glass-making materials. 
These publications, except those to which a price is affixed, can be 
obtained free by applying to the Director, United States Geological 
Survey, Washington^ D. C. The priced pubUcations may be pur- 
chased from the Superintendent of Documents, Government Printing 
Office, Washington, D. C. 

BuBCHABD, £. F. RequirementB of aand aad limestooa lor gla» makiag. In 
Bulletin 285, pp. 452-458. 1906. 

Gl^jBS sand of the middle Mianfldppi baain. In BuUetm 285, ]^. 45iM72. 


GlaflB-aand industry of Inxliana, Kentucky, and Ohio. In Bulletin 315, 

pp. 361-376. 1907. 

Notes on glass sands from various localities, mainly undeveloped. In 

Bulletin 315, pp. 377-382. 1907. 

Fenxeman, N. M. Geology and mineral resources of the St. Louie quadrangle. 
Bulletin 438. 73 pp. 1911. 

FHALii.N , W. C. , and Martin, Lawbengb. Mineral resources of Johnstown, Pa., and 
vicinity. Bulletin 447, 140 pp. 1911. 

Stose, G. W. Glass-sand industry in eastern West Virgiaia. In Bulletin 285, pp. 
473-475. 1906. 

Weeks, J. D. Glass materials. In Mineral Resources U. S. for 1883-1884, pp. 
958-973. 1885. 60c. 

Glass materials. In Mineral Resources U. S. for 1885, pp. 544-^55. 1886. 



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The following list includes a number of papers, published by the 
United States Geological Survey or by members of its staff, dealing 
with various abrasive materials. The Government publications, 
except those to which a price is afiSxed, can be obtained free by 
applying to the Director, United States Geological Survey, Wash- 
ington, D. C. The priced publications may be piurchased from the 
Superintendent of Documents, Government Printing Office, Wash- 
ington, D. C. 

AbnolD) Ralph, and Andbbson, Robsbt. Diatomaceoiu depoeits of northem 
Santa Barbara County, Gal. In Bulletin 315, pp. 43^-447. 1907. 50c. 

Chatabd, T. M. Corundum and emery. In Mineral Resources U. S. for 1883-^ 
pp. 714-720. 1885. eOc. 

Eckel, E. C. The emery deposito of Wettchester County, N. Y. In Mineral 
Industry, vol. 9, pp. 15-17. 1901. 

Holmes, J. A. Corundum deposits of the southern Appalachian region. In 
Seventeenth Ann. Rept., pt. 3, pp. 935-943. 1896. 

Jenks, C. N. The manufacture and use of corundum. In Seventeenth Ann. 
Rept., pt. 3, pp. 943-947. 1896. 

Pabkxb, E. W. Abiasive materials. In Nineteenth Ann. Rept., pt. 6, pp. 515- 
533. 1898. 

Phalen, W. C. Abrasive materials. In Mineral Resources U. S. for 1909, pt. 2, 
pp. 609-^28. 1911. 

Pbatt, J. H. The occurrence and distribution of corundimi in the United States. 
Bulletin 180. 98 pp. 1901. 20c. 

Corundum and its occurrence and distribution in the United States. 

Bulletin 269. 175 pp. 1905. (Bulletin 269 is a later and revised edition of 
Bulletin 180.) 

Rabobo, W. a. Buhrstones. In Mineral Resources U. S. for 1886, pp. 581-582. 
1887. 50c. 

Grindstones. In Mineral Resources U.S. for 1886, pp. 582-585. 1887. 50c. 

Corundum. In Mineral Resources U. S. for 1886, pp. 585-^6. 1887. 50c. 

94174"— Bull. 470—11 ^24 369 

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Read, M. C. Berea grit. In Mineral Reeources U. S. for 1882, pp. 478^79. 
1883. 60c. 

SiBBENTHAL, C. £., and Mesler, R. D. Tripoli deposits near Seneca, Mo. In 
Bulletin 340, pp. 429-437. 1908. 

Turner, G. M. Novaculite. In Mineral Resources U. S. for 1885, pp. 433--136. 
1886. 40c. 

Novaculites and other whetstones. In Mineral Resources U. S. for 1886, 

pp. 689-594. 1887. 50c. 

WooLSBT, L. H. Volcanic ash near Durango, Colo. In Bulletin 285, pp. 476-479. 
1906. 60c. 

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By R. W. Richards and G. Tl. Mansfield. 



The examination of the phosphate fields in Idaho, Wyoming, and 
Utah by the United States Geological Survey b^im in 1909* was 
continued in 1910 by three parties, two of which were engaged in 
geologic work and one in top<^aphic mapping. The investigation 
comprised a detailed study of a portion of the lands within the phos- 
phate reserve created by the withdrawals of December, 1908, and 
December, 1909, by the Secretary of the Interior, which were ratified, 
confirmed, and continued by the President under the act of June 25, 
1910, and also a reconnaissance examination of lands possibly phos- 
phate bearing outside of the reserve. The geologic parties in charge 
of Eliot Blackwelder and R. W. Ridiards were detailed to Wyoming 
and Idaho, respectively, and Albert Pike was assigned to undertake 
topographic work in Idaho. A portion of the reserve in Idaho known 
to contain extensive deposits situated near the Or^on Short Line 
Railroad was selected for the detailed examination. Base maps of 
the townships ccmtaining the largest areas of phosphate lands were 
made by the topographic party on a scale of 1 : 31,680, or 2 miles to 
the inch, this being the scale in conunon use by the General Land 
Office for surveys of the public lands. A 60-foot contour interval was 
used, and special care was observed in the location of the land comers 
and in the collection of data for the classification of the forest and 
agricultural lands. The country surveyed was in part rough and 
difficult of access, but the cost of the excellent topographic data 
obtained was about $15 a square mile, or about $500 to a township. 
The detailed maps of the present report are taken in part from the 
tO¥mship sheets made by Mr. Pike, but it is necessary, owing to the 

I Oafe, H. S., and Rlobards, R. W., PhMptaaie deposits In Idaho, Wyuning, and Utah: Bull. U. 8. OeoL 
Survey No. 430, 1910, pp. 467-536. BlaflkweMer, £ttot» Phosphate deposits east oT Ogdeo, Utah: Idem, 
pp. 636-667. 


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method of publication, to use a smaller scale and therefore to CHxiit 
much of the topographic detail. 

This paper is a progress report of the detailed geologic work for the 
year in southeastern Idaho. The authors were assisted in the field 
by J. H. Bridges and E. C. Ragar. Paleontolc^ts G. H. Girty, J. P. 
Smith, and T. W. Stanton visited the party in the field season and 
spent some time in the study of the stratigraphic problems. 


The accompanying map of the phosphate reserves of Idaho (fig. 46) 
shows the area examined during the summer of 1910 and its relation 
to the areas surveyed in 1909 and described in Bulletin 430. 

The area (covered in this report) comprises portions of Bear Lake 
and Bannock counties, in southeastern Idaho, and includes the phos- 
phate deposits near Bloomington, Paris, Liberty, and Soda Springs. 


Bear Lake Valley is the most important topographic feature of the 
area examined and extends from the south end of Bear Lake nearly 
due north as far as Bennington. Thence it turns about 16® west 
of north and continues through the rest of the district under discus- 
sion. The southern portion of the valley in this district is 6 to 8 
miles wide, but north of Bennington it narrows to about 4 miles and 
is interrupted by low hills. The altitude of the valley as a whole 
is nearly 6,000 feet. The mean surface elevation of Bear Lake, as 
determined by recent level work, is 5,924 feet above the sea; the 
elevation of Bear River south of Soda Springs is about 6,750 feet. 

Bear Lake occupies the south end of Bear Lake Valley. Only the 
north end of the lake lies in the district covered by this report. East 
of St. Charles a long, low sand bar constitutes the north end of the 
lake. North of this bar lies a detached body of water that merges 
northward into an extensive marsh. This is called North Lake and 
it varies in volume and extent with the season. On the east side of 
the lake the land rises abruptly almost from the water's edge to the 
Bear Lake Plateau, which has an average elevation of 7,250 feet; on 
the west side it rises somewhat less abruptly to the Bear River Range. 

Bear River does not enter Bear Lake but breaks through the east 
wall of the valley some 6 miles north of the lake, where it enters a 
great marsh. Thence it continues northward to the vicinity of Soda 
Springs, where it turns west, and it swings southward at Alexander. 

The northern part of the Bear River valley has been overflowed by 
basalt as far south as a point 4 or 5 miles south of Soda Springs. The 
basalt has crowded Bear River against the north end of the Bear 
River Range and has caused the remarkable bend that the river 

Digitized by 



makes at that point. The 
river here flows in a can- 
yon, the north side of 
which is basalt and the 
south side is formed of the 
limestones of the Bear 
River Range. 

The Bear River Range 
extends along the west 
side of the valley with no 
break until the transverse 
canyon of Bear River is 
reached. Beyond that 
point the range is con- 
tinued with decreasing al- 
titude in the Soda Springs 
Hills. The range as a 
whole stands about 2;500 
feet above Bear Lake Val- 
ley. The culminating 
points are Paris and Soda 
peaks, with altitudes of 
about 9,500 and 9,660 feet, 
respectively. The east 
front of the range has a 
rather steep descent near 
Bear Lake, where the Cam- 
brian quartzites approach 
the western border of the 
valley. Farther north 
younger rocks intervene 
and the slopes descend 
with longer, gentler grades. 
Near Liberty an important 
embayment in the range is 
made by the valley of Mill 
Creek, and farther north 
an outlying portion of the 
foothills is nearly isolated 
from the main range by 
the broad Nounan Valley. 

The east side of Bear 
Lake Valley is occupied 

SUCCessivelv bV the Bear Fhkhb 45.— Map showing phovhaterwerveilnldaliooii 
T 1 -Di X A* £ Juxie30,lWl. 

Lake rlateau, a portion of 

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the Preuss Range, and the Aspen Range. The general altitude of 
tliese eastern uplands is 7,000 to 9,000 feet. The cuhninating point 
is Mead or Preuss Peak, which has an altitude c^ 9,952 feet. Thus 
the maximum reUef in this district is about 4,000 feet. There Bxe 
three important interruptions in the east border of the valley, 
produced by the canyons of Bear River, Montpelier Creek, and 
Georgetown Creek. The west front of the Bear Lake Plateau 
descends steeply to the lake and forms an almost straight line that 
cuts obUquely across the strike of the upturned beds. Farther north 
this line is continued with a considerable degree of regularity by 
the ranges above mentioned. Thermal and mineral springs occur at 
intervals along this line and at some places^ especially in Tps. 10 
and 9 S., R. 43 E., and Tps. 9 and 8 S., R. 42 E., there are extensive 
deposits of travertine that appear to be associated with tliis feature 
and to indicate the presence of a profound fracture 

The topography of the uplands on both sides of the valley indi- 
cates a long erosion histoiy. The rocks are complexly folded and 
faulted and yet the upper slopes have been subdued to the smooth 
and rounded outlines indicative of late maturity or early old age. 
Beneath these wdl-wom slopes the present sharp-featured canyons 
have been cut to depths of 500 feet or more. The rainfall of the 
region amounts approximately to 10 inches annually,* so that only 
the larger streams have sufficient drainage areas to supply a perma- 
nent flow. The main streams have been able to cut their valleys 
deeply, but many of their tributaries, witli smaller and infrequent 
flow, have not cut down rapidly enough to enter the main streams 
at grade. Tributary valleys may therefore be seen hanging at 
varying heights above the floors of the main canyons. A particu- 
larly fine example of this type of hanging valley occurs on the north 
side of Middle Sulphur Canyon near its mouth, in sec. 7, T. 9 S., 
R. 43 E. Here the httle tributary hangs about 450 feet above the 
floor of the main canyon. 


The Oregon Short Line Railroad, the only transportation line of 
this district, follows Bear River. A branch line has recently been 
constructed from Montpelier to Paris, the county seat of Bear Lake 
County. Montpelier, Paris, and Soda Springs are the largest towns 
of the district, MontpeUer haviog a population of about 2,000. 

The interests of the region are chiefly agricultural. Bear Lake 
Valley and the adjoining bench lands are fertile and occupied by 
many ranches and farms. 

The higher, open ground is utilized for sheep raiiges. Soda 
Springs and Montpeher are important shipping poipti^. 

s Henry, A. J., Climatology of the United States: Bull. Weatber Boieaa No. 861, U. S. Dept. Agr., 1906k 
pp. 822, 823. 

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The phosphate industry is represented in this district by the San 
Francisco Chemical Co., the Utah Fertilizer & Chemical Manufac- 
turing Co., Brown, Perkins & Co., and Duffield & Jefifs. . Thus far 
shipments have been made only from the Waterloo niine, at Mont- 
pelier, by the San Francisco Chemical Co., aad a single shipment 
from one of the claims held by Brown, Perkins & Co., at Soda Springs, 
in the SE. i SW. i sec. 23, T. 8 S., E. 42 E. 


The springs and their extensive deposits near the present town of 
Soda Springs figure in the narratives of the early explorers Bonne- 
ville ^ and Frfimont,^ but no other account of the geology is known 
previous to the r^)ortB of the Hayden Survey ' for the years 1871 
and 1877. 

Weeks and Ferrier ^ published in 1908 a general accoimt of the 
western phosphate fields with brief Ascriptions of several localities; 
includiDg the Swan Lake district (T. 9 S., B. 43 E.). 


The rock phosphate is characterized by an oolitic texture, which, 
however, may be lacking when the grain of the rock has been de- 
stroyed by pressure or by shearing. The ovules or oolites are rounded 
grains built up in roughly concentric structure and ranging in size 
from extremely minute specks to bodies half an inch or more in 
diameter. Many of these oolitic bodies are irregularly flattened, 
suggesting that they may have actually existed as pebbles and been 
worn by attrition upon one another. The ovules are in general of a 
darker color than the matrix and a few of them possess a black shiny 
coating which is similar in appearance to desert varnish. In the 
one quantitative comparison that has been made the ovules were 
found to be 3 per cent higher in content of phosphoric acid than the 

The freshly mined rock usually possesses a dark-brown color, but 
the weathered material found on the outcrop is predominatingly a light 
bluish gray. The rock that has lost its oolitic texture through pres- 
sure metamorphism appears to retain the darker original color even 
after long exposure. The bluish-gray coating (somewhat like chal- 
cedony in appearance) has a tendency to concentrate along lines in 
a netlike pattern. These lines are very apparent upon the darker- 

> IrviDg, Waablngton, The Rocky Momitaiiw, etc, from the Jooniel of Oapt B. L. X. BoimevUle, 1878. 

s Frfinumt, J. C, Report on the ezploriog eagpetUtton to the Rocky Mbontalns In 1843: Senate Doc. 174, 
House Doc. 166, 28th Cong., 2d sen., 1845, p. 093. 

s Hayden, F. V., Fifth Ann. Rept. U. 8. OeoL and Qeog. Survey Terr., 1871; Idem, Eleventh Ann. 
Repi., 1877. 

« Weeks, F. B., and Ferrier, W. F., Phosphate depodlatn weetem United States: BuU. U. S. Oeol. Sur- 
vey No. 340, 1906, pp. 441-447. 

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876 OOmnMBUTIONS to economic QEOLOGY, 1910, PABT !• 

colored rock and are of assistance in following scattered float along 
the concealed outcrop of the phosphate beds. 

The phosphate rock and the limestone closely associated with it 
when struck yield a characteristic fetid odor which is described by 
some as bituminous and by others as more nearly sulphurous. One 
feature on which all agree is that the odor, though not particularly 
disagreeable, is exceedingly penetrating. The intensity of the odor 
given off by any portion of the rock when struck is by no means an 
indication of its phosphatic content. 


A series of experimental determinations of the density of the rock 
phosphate was made in the laboratoiy of the United States Geological 
Survey and is described in detail in the report for 1909. The average 
specific gravity for rock containing 70 per cent of tricalcium phos- 
phate was found to be about 2.9. No further data on this subject 
have been collected and the above figure has been used in the ton- 
nage calculations of the present report. 



The rock phosphates of the western fields occur as deposits inter- 
bedded in strata of undoubted sedimentaiy origin and according to 
the interpretation of fossil data are regarded of Pennsylvanian age. 
They were deposited at about the same time geologically as the 
extensive coal deposits of the Appalachian r^on. Like the coal 
deposits; they have been subject to deformation by folding and 
faulting, but they have suffered less from metamorphic changes, 
which are indicated only by a loss of the original oolitic texture, the 
chief microscopic characteristic of the phosphate rock. This oolitic 
texture is undoubtedly significant as to the origin of these deposits 
and is regarded by the writers as original rather than secondary. 

If the oolitic bodies were secondary or produced subsequent to the 
deposition of the beds the bedding planes might appear in at least the 
larger oolites, but such traces of bedding are wholly absent. An 
unusual facies of the phosphate was collected from the base of the 
high-grade bed in sec. 2, T. 8 S., R. 42 E., which consists of shell 
fragments that G. H. Girty * is inclined to regard as derived from 
pelecypods. The phosphoric acid content of this specimen (33.8 per 
cent P2O5) is that of a high-grade rock. 

The shells of pelecypods, so far as known, are composed of prac- 
tically piure lime carbonate, and it seems more reasonable to assume 
that this deposit is due to the phosphatization of lime carbonate 
shells rather than to the existence of an unusual phosphate-secreting 

^ PcraonBl wF"i"* nn1in>1iiftH ■ 

Digitized by 



fomL Qirty, however, states that lAngula discina, a phosphate- 
secreting brachiopod, is prominent and abundant in the Embar forma- 
tion of Wyoming, which in the area recently examined by Woodruffs 
may prove equivalent to the Park City formation, and a few speci- 
mens were found by Gale ' in the main phosphate bed at Cokeville, 
Wyo. The question is raised whether or not the evidence indicates 
that such forms predominated sufficiently over the lime carbonate 
secreting forms to account for the immense accumulation of phos- 
phoric acid represented by the contents of the western fields. 

George A. Koenig' has advanced a hypothesis that the lime 
phosphate was secreted by a protozoan of unknown type, which was 
extremely prolific and accumulated a great bulk of material in a 
short time. The writers regard this suggestion as improbable but 
can not in the present report enter into a detailed discussion of the 
data and inferences involved. It may be said, however, that a 
hypothesis adequate for the explanation of the extensive phosphate 
deposits of the western fields, must consider: (1) The source of the 
phosphoric acid; (2) the conditions that resulted in the abnormal 
enrichment of the sea water in the acid or ita salts; and (3) a cause 
for the abstraction of the acid in the form of lime phosphate and its 
deposition in oolitic bodies. 

The formulation of such a hypothesis requires the assembling of 
further data concerning the geologic constitution of the land areas 
bordering the epicontinental sea in which the phosphates were de- 
posited. The writers hope to advance, after such data are collected, 
a scheme of origin in which the constitution of the land areas imme- 
diately adjoining the sea, the chemical constitution of the atmosphere 
(which contained CO3 in greater abundance than at present), and the 
character of the basin or basins in which the deposits were formed 
will all be considered. It is thought that the hypothesis wiU suggest a 
direct chemical and physical origin rather than one in which organisms 
play a prominent part. 


The mineral composition of the western rock phosphate is not yet 
completely ascertained, and the problem is difficult of solution, owing 
to the mode of occurrence of the constituent minerals. Thin sections 
of the richest oolitic ore show under the microscope that the rock 
consists mainly of ovules or concretions of a cryptocrystalline sub- 
stance which, in some concretions, is smrounded by banded zones of 
crystalline fibers with local isotropic bands, all having the same 
average index of refraction (about 1.60) and apparently representing 
the same substance — ^the phosphatic mineral. In some places the 

i WoodruflfE. 0.,The Lander oil Add, Wyoming: BuH XJ. S. OeoL Stiryey No. 452, 1911. 

* Penonal oominanication. 

• Quoted by M. 8. Dofflald in lilnM tnd Metfaods, voL 2, No. 1, 1910, p. 12. 

Digitized by 



interstices are Med with caldte and in otheis with an isotropic mate- 
rial which appears to be identical with the substance forming the 
cores of the concretions. The ovules include minute cudiy, hairlike, 
and branching plant fragments whose appearance strongly suggests 
that they represent fungi. The exUnction of the double-refracting 
mineral is parallel to the elongation of the fibers, but the optical char- 
acter of this mineral can not be determined because of the absence of 
cleavage or crystal faces. 

Additional mineridogieal data have been obtained from the unusual 
facies of phosphate rook collected from the base of the main bed in 
sec. 2, T. 8 S., R. 42 B., which is regarded as conq>osed of fragments 
of pelecypod shells. An examination of a thin section of this rock 
(R 307) and others of the ooUtic variety was made by W. T. SchaUer, 
of the United States Qeological Survey, who regards the isotropic 
substance as probably representing coUophanite, x((\(PO^)i) or 
a:((CaF2)Ca,P04)«H-j/CaCOa-faHjO and the double refracting sub- 
stance as possibly quercyite. Quercyite comprises a variable mix- 
ture of the series of lime-phosphate minerals, including coUophanite 
described by Lacroix ^ from the French phosphorites. 

Chemical analyses of the rock phosphate of the western fidd are 
published on page 465 of the 1909 report. No additional complete 
analyses have been made, and no reason has appeared for modifying 
the 1909 statement that the calcium phosphate mineral closely ap- 
proximates in composition a basic calcium phosphate. 


The field quantitative determination of phosphoric acid was aban- 
doned in 1910, and the determinations pubhshed in this report were 
made by Henry A. Lepper and John Q. Fairchild in the chemical 
laboratory of the United States Geological Survey. 

A number of the field determinations published in the 1909 report 
have been reviewed and found to run from 1 to 2 per cent high, 


A tendency toward enrichment of the content of phosphoric acid is 
shown in the weathered outcrops of the rock-phosphate beds. As 
this would naturally be expected from the chemical and mineralogical 
composition of this material, no extensive examination has been 
imdertaken to verify this conclusion. In the 1909 work at Mont- 
pelier an average sample of the main bed taken at the surface ran 4 
per cent higher in phosphoric acid than the average samples taken in 
the Waterloo mine, and J. J. Taylor, the superintendent of the prop- 
erty, reports that a still lower content was found in the bed as cut by 

1 Lacroix, A., Sur la oonstitutton mintoUogique des phosphorites franoais: Compt. Rend., vol. 150^ 1910^ 
p, 1213; Minftnvlogie de la France, vol. 4, pt. 2, 1910, p. 555. 

Digitized by 



a bore hole at comparatively shallow depth. This evidence is prob- 
ably insufficient on which to base general conclusions, but the mining 
operations in other parts of the field seem to demonstrate that fresh, 
clean rock from the thicker workable beds usually maintains an aver- 
age content exceeding 32 per cent of phosphoric acid in the area 
examined during 1909. The average for the area described in the 
present report, however, would probably be slightly lower. 

Positive information about the character of these deposits at greater 
depth is needed, as it must be admitted that all the data collected at 
present have come practically from the outcrop, and only theoretical 
foundation exists for statements concerning the character of the 
greater volume of the rock included in the tonnage estimates. 

The importance of the phosphate deposits still in pubUc ownership 
is greatly enhanced if only the outcrop of these deposits is of present 
commercial value, and it is therefore imperative that a study of the 
quality of these deposits under cover should be conducted by system- 
atic drilling prior to their disposal and development. 


Iron and alumina in phoi^hate rock in excess of 3 to 4.5 per cent 
in the eastern fields are considered as placing the ore below foreign 
contract standards. These substances are supposed to produce in 
the present process of superphosphate manufacture deUquescent salts 
which render the drying and shipment of the product difficult. The 
several ultimate analyses of samples of rock phosphate from the 
western fields by Qeoi^e Steiger * published in the 1909 report give 
both iron and alimiina determinations. A number of additional iron 
determinations made recently by Steiger on samples of phosphate 
from the vicinity of Bloomington, Idaho, range from 0.30 to 0.45 per 
cent. In all samples from these fields that have been tested in the 
laboratory of the Geological Survey less than 1 per cent of either radi- 
cle computed in the oxide form was found. The manufacturers of 
superphosphate using the rock from the western field all agree that 
the amounts of these substances present are too small to be considered 


Metamorphic changes are effected in the rock pnosphate by pressure 
and also by solution. The loss of oolitic texture and an apparent 
slight increase in density has been noted in places where the phos- 
phate has been subjected to excessive compression in the deformation 
of the inclosing strata. A somewhat porous facies has been found 
which indicates that partial solution of the rock has been accom- 
plished, probably by the carbonated water with which the springs of 
the northern part of the area abound. 

1 BulL U. 8. OeoU Survey No. 430, 1910, p. 465. 

Digitized by VjOOQIC 




The rocks of the area surveyed in 1910 (see PI. IX) are mainly 
sedimentary, with a stratigraphic range from Middle Cambrian to 
Quaternary, but in the extreme northwestern part there occur 
basaltic flows which have generally been regarded as of the same 
age as the flows of the Snake River lava plains.^ Late Tertiaxy 
beds cover an area of about 50 square miles. An overlap with Ter- 
tiary beds lying on Triassic or Carboniferous rocks, thousands of 
feet of beds which are prominent in the areas to the south and east 
being absent, is the most significant stratigraphic feature of the 
region. The most prominent structural feature consists of a great 
easterly overthrust which crosses the area from north to south and 
causes rocks of Middle Cambrian to Mississippian age to overlie 
Triassic(t) sediments. 

A compiled tabular sununary of the stratigraphy of the- area is 
given below. The several formations are described in greater detail 
in the pages following the table. 

General eection ofphosj^uUe area in Idaho. 






Not measnTBd. 

AUuvium, travertioe, basalt flows. 



White maris, martj UmeBtanae, 
oaloanoQs ooncloinflratBs; dense, 
nearly littaographio UmestooBs near 
Soda Springs; pea-green grits. 


Roadily bedded ooaise aandstooas 
and coaxae oonglomerates or bowl- 
der beds, In piaoes of a deep rod 

-TJnoonformity — 



Agglomerate (of fiault origin?) oom- 
posed of franoents and masses of 
voleanio asb (white toff) and 
rboniferoos i 

Triasslo and Carb 

I rooks. 

Trlassio or Carbonlf- 
ennis (indading the 
Middle and Lower 
Triasslo of Hyatt 
and Smith). « 

— Unoonfonnlty- 
Ankareh Shale. 

670 feet near Mont- 

Consists essentially of red shale and 
mottled red and greenish day and 
shales, with some sandstone and 

Thaynes limestone. 

About 2,000 feet or 

The main bodv of the formation 
consists of darlc-blQe UmestODe, in 
many piaoes fossUiferous, weather- 
ing to a brown maddy color, also 
including sandy and calcareous 

Woodside limestone. 

1,000 feet in the 
PreosB Range. 

Thin-bedded platy limestones, some- 
what sfaaly and landy. 

a Hyatt, Alpheus, and Smith, J. P., The Triassic cephalopod genera of America: Prof. Paper U. 8. OeoL 
Sorvey No. *5, 1905, pp. 17 et seq. 

i RussBll, I. C. BolL U. 8. Gaol. Snrvay No. 19B, 1893. 

Digitized by 







Digitized by 



Digitized by 



Oeneral teetUm ofphosphaU area in Idaho — Continued. 





Firk City fonna- 600 to 860 fast. 


A lonnatioa Inolndlng three mem- 
bers as follows: 

(a) One or more massivB strata of 
otMTty Umestone or dbort, promi- 
nent as a ledge maloer, grading In 
part to a poipUah eherty or ftmty 

(fr) Rook pbosphato.phosphatie shale 
and mlqor Umestone bands. ' 

(e) I^bTiflstone, massive white to light 
Mulsh, granular, weathering with 
protecting fossU fragments, usually 
wHn bluish chert bands and in 
some localittes black chert in 
rounded nodules in the lower 

1,000 ^Iset. 

White sandstone and quartzito, cal* 
careous sandstones, and light- 
colored limestones, with yariable 
amounts of intarbedded quartsites. 

Morgan <7) forma- 

Madison Ifanestone. 




Light-colored limestone with inter- 
bedded sandstones. 

1,300 ± feet 


lulsh-gray limestones with spherical 
nodules of black chert; nay sandy 
limestone streaked with caldte 
and specked with slderlto: locally 
maikad by fossil corals and crinoid 


Kassive blue to gray limestone, a 
th M f Ibimation usually rnRiring 
high mountainous country where 
brought to the surface in mass. 


(?) Ume- 

Not measured. 

Dark-gny to black limestone. 


Not measured. 

I>ark eherty Itanestone; tiihi-bedded 
and light-grey sandy limestone. 


Not measured. 

Lhnestone, eherty limestone, guarts- 
Ito with some shale, ana gray 


DlTlded faito six 
fbrmations by Wal- 

6,000 + feet. 

Limestones and quartsites with a 
few beds of shale. 


The rocks of the western portion of the area comprise a series of 
limestones and quartzites which have been studied in detail by 
Walcott ^ and referred on abundant fossil evidence to the Cambrian. 
The following section is compiled from his publications. 

> Waloott, G. D., Nomenclature of some Cambrian CordHleran formations: Smithsonian Inst. ICiso. 
CoU., vol. 63, 1906, pp. 1-12; Cambrian sections of the Cordilleran area: Idam, pp. 167-230. 

Digitized by 



Geologic gection on MiU Creek west of Liberty ^ Idaho, 

Upper Cambrian: Fmi. 

St. Charles limeBtone: Bliush-gray to gray arenaceoua lime- 
stones, with some cherty and coocretioiiary laye»» passing 

at the base into thin-bedded gray to brown sandstones 1, 197 

Middle Cambrian: 

Nounan limestone: Light-gray to dark lead-colored arenaceous 
limestones 814 

Bloomington formation: Bluish-giay, more or less thin-bedded 
limestones and argiUaceous shales. Small rounded nodules 
of calcite are scattered irregularly through many of the 
layers of limestone 1,162 

Blacksmith limestone: Gray arenaceous limestone in massive 
layers 23 

Ute limestone: Blue to bluish-gray thin-bedded fine*grained 
limestones and shales, with some oolitic, concretionary, 

and interformational conglomerate layers 731 

Spence shale member: Argillaceous shales 30 

Langston limestone: Massive-bedded bluish-gray limestone 
with'many round concretions 30 

Brigham quartzite: Massive quartzitic sandstones 1,000+ 

These formations outcrop along the east side of the Bear RiTer 
Range, and in all pIcu^e8 where it was examined the margin of the 
OTerthrust consists of the Ute and Langston limestones or the Brig- 
ham quartzite. Spence Gulch, the type locality for the Spence 
shale member of the Ute limestone, was visited, but no attempt 
was made to map the several formational units as laid down by 


Limestones and quartzites of Ordovician age were found west 
of St. Charles and north and west of Soda Springs but were not 
studied in detail. The fossils collected from the limestones at this 
point are referred by E. O. Ulrich' mainly to the Beekmantown 
horizon of the East. The most extensive faxma collected is iden- 
tical with a fauna from Malade, Idaho,' and a fauna collected by 
Sidney Paige * near Silver City, Grant County, New Mex. 


Limestones containing fossils which are identified by E. O. Ubich 
as basal Silurian were collected in the southwest comer of T. 8 S., 
R. 41 E. Lithologically this portion of the section is characterized 
by gray and black limestones, more or less brecciated and cut by 
streaks of calcite, associated with rough-weathering sandy lime- 
stones, which are reddened by limonite stains. 

1 Personal communication. 

» Meek, F. B., Sixth Ada. Kept. 17. S. QttiL and Q«Qg. Survey Tair., 1872, p. 469. 

Digitized by 




A dark, nearly black, magnesian limestone has been found in 
T. 10 S., R. 43 E., which contains fossils identified by Eindle as 
Atrypa rdicularis, ProdudeUa close to svlniculeata^ FavosUes cf. 
limitaris (most abimdant), IHpli/yphyUuin sp. undet., and Oystiphyl- 
lum sp. undet. Favosites cf. limitaris is one of the characteristic 
species of the Jefferson limestone of Montana, and its presence in 
the fauna, together with the resemblance of the dark magnesian 
limestone holding the fauna to that of the Jefferson, suggests that 
the collection represents that formation. 

Another collection made in T. 8 S., R. 41 E<, from a magnesian 
limestone that contained numerous specimens, is said by Kindle to 
be comparable to Favosites digUatus, which is provisionally referred 
to the Devonian. 



The basal Carboniferous sediments of the area are heavy beds 
of light-gray limestones, which where favorably situated resist ero- 
sion effectively and make rugged topographic features. The fauna 
collected from these beds is referred by G. H. Girty to the Madison 
limestone, which according to Girty corresponds to the basal por- 
tion of the ''Wasatch limestone'' of the Wasatch Motmtains of 
Utah as described by the early writers. 


Above the Madison limestone, apparently in conformable suc- 
cession, there is in this region about 1,200 feet of limestones, includ- 
ing dear bluish-gray limestones with spherical nodules of black 
chert and gray sandy limestones streaked with calcite and speckled 
with siderite and locally marked by layers in which zaphrentoid 
corals are abundant. This interval includes the Ross Fork-Lincoln 
Creek (Idaho) fauna of Meek,^ which is comparable to that of the 
Spergen limestone of the central basin region of the United States. 

The following section shows in detail the upper 435 feet of the 
upper Mississippian and the lower 560 feet of tiie overlying Penn- 
sylvanian, which is tentatively correlated with the Morgan formation. 

1 ICeek, F. B., Sixth Aim. Kept. U. S. Qeol. and Oeog. Survey Tecr., 1872, pp. 47(M71. 

Digitized by 




Section jneatured in tee, $9, T.9 8., R.4S E.^inSwanLakeOuUh. 


Moigan (?) formation — 

Concealed. Tmiu 

Limestones, light colored, with chert nodules and inter- 
calated quartzitic layers. Bryozoa and Syringopora 
abundant at the top but not found in place; Ch(meU$ and 

Stenopara 100 feet from the top, also in float 375 

Sandstones, gray, interbedded with gray limestones and 

light-colored chert; Schizdphora abimdant near top 150 

Limestone, light blue, fine grained; a ledge maker; 

Chonetesf 35 

Upper Mississippian : 

Limestone, dark gray, piire, in part oolitic, and some light blue 
or lavender lithographic limestone with the Ross Fork-Lin- 
coln Creek (Idaho) fauna of Meek ^ abimdant at top, and corals 

abundant toward the base 65 

Limestone, dark gray, pure, in part streaked with calcite and 

specked with siderite; full of rather small zaphrentoid corals.. 150 
Limestone, quartzitic; fenestelloid Bryozoa and zaphrentoid 


Limestone, gray, siliceous, more or less cross-bedded with thin 

shaly bands; some chert 



The upper Mississippian limestones are succeeded, with apparent 
conformity, by about 500 feet of soft sandy limestones of reddish and 
yellow tints intercalated with a minor amount of clear blue-gray fos- 
siliferous limestones from which many collections have been made. 
CSonceming these f ossils; Girty says : 

In general these Idaho faunas have a facies closely similar to the Moigan fauna as 
represented in Mr. Blackwelder's collections from Weber Canyon, and they therefore 
indicate a correlation with the Morgan. As many of the species had a long range in 
other areas and as the fauna of the Weber quartzite in Weber Canyon is practically 
unknown and may prove to be the same as the Moigan fauna, a certain element of 
doubt still remains. On the other hand, these Idaho faunas succeed others of upper 
Mississippian age, just as the Moigan ftiunas do in Utah, and there is an interval be- 
tween them and the Park City formation which has thus far furnished no fossils cone- 
sponding to the Weber quartzite in Utah, though not very similar to it lithologicalJy. 
The Idaho faunas are especially characterized by an abundance of branching Bryozoa, 
belonging chiefly to the family Batostemellid^e, a feature which is not found in the 
typical Moigan. 

No attempt has been made to differentiate the beds which may sub- 
sequently be referred to this formation on the preliminary maps that 
accompany this report. 

1 Meek, F. B., loo. oit. 

Digitized by 




The Weber quartzite in the area examined in 1909 consists chiefly 
of massiTe white quartzite with subordinate amounts of shale and 
calcareous sandstone or limestone. In the region studied during the 
present year the conditions are practically reversed, and the true 
quartzite is subordinate to calcareous sandstone and limestones. 
The character and position of the small amount of quartzite present 
are extremely variable. It was found so impracticable to locate the 
exact top, and especially the bottom of the quartzite, that attempts 
to map it were abandoned. The beds that are present in this interval, 
which has been mapped as Weber quartzite elsewhere, merge so 
gradually into the underlying sediments that they have not been 
difiPerentiated from the Morgan (t) formation and the underlying 
Mississippian limestones on the maps that accompany this report. 


The Park City formation was named for the Park City mining dis- 
trict, Utah/ where it is said to have contained the principal bonanzas 
for which that district is known. The correlation of corresponding 
strata in southern Idaho and northeastern Utah with the Park City 
formation of the central and southern Wasatch regions is based on 
faunal and lithologic correspondence between the sections of the two 
regions; this similarity is indeed remarkable considering the dis- 
tance by which the areas are separated. In the recent study of the 
phosphate beds, however, much more complete evidence of the con- 
tinuity, especially of the beds associated with the phosphate, has 
been found, and the phosphate has been identified in the correspond- 
ing position in the Park City section. So exact is the lithologic cor- 
respondence that the thicknesses and descriptions given for the Park 
City district ^ are almost directly applicable to the Idaho sections. 

The Park City formation is divisible into three parts — (1) an upper 
cherty limestone; (2) an interval of phosphatic shales, phosphate rock, 
and limestone bands; and (3) an underlying limestone, usually mas- 
sive and conmionly containing much chert. 

The massive ledge-forming stratum of chert or cherty limestone 
immediately overlying the phosphate-bearing shales is distinguished 
as a separate member, on account of its prominence and its value as 
a horizon marker from which to trace the outcrops of the phosphate 
beds themselves where they are not continuously exposed. This 
member has been referred to locaUy as 'Hhe cherty lime," ''the Pro- 
ductus limestone," or "the overlying limestone." In the districts 
examined in 1909, except in the Montpelier district, it consists of 

1 Boatwell, J. M., Stratigraphy and struotuie of tl» Park City oiiiiin^ dl9trict| Utab: Jfoqr. Qeolo^^ 
VOL U, 1907, pp. 434-458. 

W174*— Bull. 470—11 26 

Digitized by 



black chert, dark chertj limestonee, and a minor amount of bluish- 
gray limestone and is quite distinct from the brown shaly limestones 
of the lower part of ibe Woodside shale, overlying the Park City 
formation. North and west of the^e districts the member has under- 
gone considerable modification, both in thickness and litbologic 
character, and daric-^olored siliceous or cherty shale which weathers 
pink to brown is the most prominent characteristic of the member. 
The cherty shale attains a maximum thickness of about 450 feet. 
Locally, however, heavy beds of chert vary from cream, pink, yellow, 
brown, or dark blue to nearly black in color. Another variation 
observed in Wood Canyon, in T. 8 S., B. 42 E., consists in the presence 
near the base of a coarsely granular gray limestone crowded with 
large crinoid stems, with minor thin intercalated beds of bluieh-black 

A review of the MontpeUer district during the sununer of 1910 shows 
that a shaly bed is present within the cJiert and that a small amount of 
jHTospecting had be^i done on it in the search for phosphate. This 
occurrence is interesting for comparison with the rather extensive 
shaly strata which are devdoped to the north, in the Aspen Range, 
and with the discoveiy of a pbosphatic stratum within the chert mem- 
ber of ccMrresponding beds in Wyoming, as described by Blackwelder 
on pages 452-481 of this bulletin. 

The ^^Pfwhutua limestone'' contains some characteristic fossils, 
in the main species of Productus, These are as a rule limited in occur- 
rence to the chert and the clear blue-gray limestones, the shaly por- 
tions of the membo* being practically bairen. Oirty calis attention 
to the fact that only three coUeetions were obtained from this lime- 
stone in 1910 and Usts the forms Productus semire^culatua, P. aff. 
sfibhorridus, Margimfera splendensf, and Spirifer afl. mkUini, 

The areas examined in 1909 contain Productua aemireticulatus, 
P. humioldii, and P. subhcrridusf, and in some beds Spiriferina 
pvlckra and Stenopora are found in relatively greater abundance 
tiian ProAaeius, being commonest in lones near the top of the cherty 
limestones. Locally in portions of the area studied in 1910 numerous 
crincnd stems are found both in diert and in coarse gray limestone 
near the base of the member. 

The phosphate*bearing member of the Park City formation, includ- 
ing all the main phosphate beds, consists of 77 to 140 feet of massive 
brown to gray phospkalic sandy shales and beds of rock phosphate, 
with some limestone and in plaoea chsrty bands in the upper part. 

The occurrence of roimded or oval limestone nodules, ranging from 
a few inches to several feet in diameter, is a characteristic feature in 
the phosphatic shales. 'Hie nodules consist of very dense, compact 
fine-grained limestone, having a fetid odor when struck with a 

Digitized by 




hammer^ but showing a low perc^itage of phoephoric aeid wh«reyei 

Many detailed sections were measured in the phosphatic shaleSi 
especially in those immediately associated with the main phosphate 
beds. By reason of the weaker constitution of these shaly rocks 
they commonly gire way to weathering and decay at the surface, 
and the outcrop is usually concecJed as a whole or in greater part. 
Float of the harder rock phosphate remains in the soil and is veiy 
readily detected by one who has become familiar with the peculiar 
appearance which is due to its oolitic texture and the characteristic 
bluish-gray bloom, concentrated in reticulated pattern upon the 
exposed surfaces. 

A complete section of the phosfdiate shales was measured under 
particularly favorable conditions in Georgetown Canyon in 1909, 
and as the section is situated only a few miles east of the middle of 
the region discussed in the present report, it is repeated for com- 

CompleU Mection of the phMphaU-bearing strata in Georgetown Canyon, Idaho. 

No. of 










Shale, calcareous, or muddy limestone, brown, weathering hito 

irregular chip fMmente; effervesces vigorously 

Phasphate rock, oolitic, weathering brown or gray; effervesces 

sligntly; lower 1} inches somewhat cherty 

Shale, hard, brown, calcareous at the top; effervesces vigorously . 
Phosphate rock, coarsely oolitic, gray; effervesces vigoroa<dy. . 
Shale, brownish, earthy, containing 6 inches of phosphate; effer- 
vesces considerably 

Phosphate rock, taicluding— Ft. in. 

^ Phosphate rock, oolitic, hard, gray, calcareous. . . 

Phosphate rock, medium, gray, oolitic 

Shale, phosphatic, light brown 

(Sample shows considerable effervescence.) 
Phosphate rock, hichiding— 

(a} Phosphate rock, coarsely oolitic, gray, brittle 

fb) Phosphate rock, finely oolitic, brownish gray 








m Phosphate rock, coarsely oolitic, dark gray.. 
(a) Phosphate rock, finely oolitic, brownish gray. 
(0 Phosphate rock, coarsely ooUtio. giay . 

v^-,. *-. . ,,^ . •^•- ,t6lnb€^ 

in Phosphate rock, finely oolitic, thin bedded 

(17) Phosphate rock, ooarselv oelitie, ga^ 1 

(Sample effervesces sUgntly.) 
Phosphate rook, including— 

(a) Phosphate rock, mediim to finely oolitic, brown- 
ish gray 

(b) Shale, phosphatic, brownish, somewhat ooUtic.. . 

(e) Phosphate rock, coarsely oolitic 

(rf) Phosphate rock, shaly, orown 

Phosphate rock, including— 

(a) Phosphate rock, coarsely oolitic, brownish-black 


Cb) Phosphate rock, shale, brown, thin bedded 5 

(e) Phosphate rock, coarsely ocditic, crmnbly 4 

(a) Phosphate rock, medium to coarsely oolitic 3 

1 1 

(Sample effervesces considerably.) 

.brownish to black, earthy compt«iuvu. u 

_ with a few limestone lenses; effervesces slightly 

Shale, brownish to black, earthv composition, thin bedded, 

Limestone, dark, compact, fetid 

Shale, brownish to black, earthy; effervesces slightly. 

a Phosphoric add determinations by W. H. 

24.2 53.0 

ii.*7"i 2&6 

Waggaman, Bureau of Soib, U. S. Dept. Agr. 






lent to 











Ft. in. 

25 6 

2 11 

1 £ 

4 2 

1 10 

4 10 

8 9 
1 9 


Digitized by 


Compkle $ectum of the photphate-hearing ttraia in OeorffeUnm Canyon, Idaho — Coatd. 

No. of 



lent to 




Shale, tnclndln^- Ft. in. 

(a) Shale, brownish black, earthy 7 

(6) Concealed, not Inoladed In 8anq>le (probably 

sameasaandc) 4 7 

(e) Shale, brownish black, earthy 5 6 

Shale, black, earthy; effervesces silently 







FU in, 


1. Shale, brownish black, earthy 






ness not aetermmed. 







Jiy; effervesces 




4 10 



2 8 


w to medlom, 
kks of shaly ma- 



6 4 


series." Thick-' 


139 11 

A partial section of the phosphatic beds was measured in 1910 in 
a prospect opening in Diamond Gidch, on the west side of the Aspen 
Range. This locality is about 12 miles from the Georgetown Canyon 

Partial section of the phosphate-bearing strata in Diamond OiUch, in the NW. \ NW. { 

sec. SS, T. 9 S., R. 4S E. 

No. of 




M 316a 


Rather thick bed of phosphatic, sandy and shaly rock, brown, 
more or less broken 

Thin dark shale and limestone, mostly covered 

Dense phosphatic dark-brown limestone, slightly fosslUferoos. . 

Dark pnospnatlo shale 

FoasHuerous limestone, modi broken and sheared 

Brown shale 

Brown sandy and shaly phoephatio rock with a few large 
oolitic erains 

Coarse oolitic phosphatic rock 

Llght^olored limestone, somewhat ooUtIo and fossUiferoos — 

Brown oolitic shaly phosphatic rock 

Much broken cone, mahily phosphatic aihales 

Li^t-brown shales 









4a 19 



Ft. in. 

2 7 





3 4 


20 Ik 

a Less than 1 percent. 

Digitized by 




The main bed of rock phosphate is exposed and is 1 foot thinner 
than m the Georgetown Canyon section. The quality of the rock is 
equaUy good. In Georgetown Canyon the main bed is only 9 inches 
aboTe the imderlying limestone, but in Diamond Gulch the interval 
between the limestone and the main phosphate bed is about 6 feet. 
Another difference consists in the presence of 17 inches of phos- 
phatic shale between the phosphate bed and the cap limestone. 

A complete section was measured on a small tributary of Slug 
Creek just east of the east boundary of T. 8 S., B. 43 E., about 26 miles 
north-northwest of the Georgetown Canyon locaUty. The. section 
which follows is the leanest in phosphate material yet obtained and 
only a small portion of the series was regarded as phosphatic. The 
beds that were sampled are indicated by numbers. 

Complete section of the phosphate-hearinq strata in the 8W. } SW, i see. 7, T.8S.,R.44 E, 
of the Boise jneridianf Idaho, 

No. of 






B 87MS 
R 878-6 

R 378^ 
R 378-3 

R 378-2 
R 878-la 
R 378-1 

Sandstone, white, fine grained, weathecB brown 

Shale, brown, sandy, with limestone lenses 

Umestone, graviah olack, fine grained, compact, fetid 

Phosphatic rock, black, coarsely ooittic 

Limestone, grayish black, fine grained, compact, fetid 

Shale, brown, with some ooUtk) streaks 

Limestone, gra3rish black, fine grained, compact, fetid 

Shale, brown, with some oolitlo streaks 

Phosphate rook, grayish black medium oolitic 

Shale, brown, thS%dded, slightly oolitlD 

Shale, brown, finely oolitlo 

Shale, brownish black 

Umestone, gray, fine grained, fetid 

Shale, brownish black 

Phosphatic rock, brownish black, finely to coanely ootttlo.. 

Phosphate rock, brownish black, shaly 

Phosphate rock, brownish black, finefy oolitic 









Ft, <fl. 








76 7 

A comparison of this section with the Georgetown Canyon section 
shows its striking inferiority both in the quantity and in the quality 
of the phosphate. That this variation is a local one rather than a 
general change in the character of the deposits is shown by the 
Diamond Gulch section and also by the f ollowiiig partial section of the 
lower part of the phosphate shales measured near the west border of 
the township, in Trail Canyon. At this place there is 7 feet of 
phosphate rock containing over 70 per cent of tricalcium phosphate 
and about 5 feet more which ranges from 65 to 68 per cent. The 
section as exposed in Trail Canyon shows relatively a greater amount 
of high-grade phosphate rock than that present in the similar portion 
of the Georgetown Canyon section. 

Digitized by 



Section of the Park City formatiion in Tndl Cannon, $ec. ;?5, T. 8 S., R, 4f E. 

No. of 



Chert, blubh black to gny. In beavy beds alternating with 
oherty ehales , 

Concealed by heavy cherty talus , 

Phoepbfttlcrock, brown, medium toflndy eoUtlc 

Limestone, gray, shaly m middle 

Shale, brown rock , 

Phosphatlc rock, brown, medium oolitic , 

Bhale, brown 

Phosphatlc rock, brown, weathers gray 

Phosphatlo rook, brown, containing '"- 

Shale, brown 

Shale, brown 

Phosphatlc rock, brown , coarsely oolitic 

Phosphate rock, brown, medium ooilitlo 

Fhosphatftc rock, brown, finely oolitic 

Shale, brown 

Lfanestone, brownish ^ray, contains Proinehu and fuoold-like 

Chert, bluish black 

Limestone, gray, one bed 

Limestone and ashy-gray chert alternating 

Limestone, gray to yellow,8oft and In part sandy 













388 6 

8a 6 

Unfortunately in this locality the upper portion of the phosphatlc 
shales is so coTered with heavy talus derived from the overlying 
limestone or chert that no prospecting has been done and the char- 
acter of that portion is undetermined. Phosphatlc beds are found, 
as in the Georgetown and Montpelier districts, near the underlying 
limestone which forms the basal member of the Park City formation. 
The cap limestone with its cJiaracteristic fossils of the same districts 
is, however, either entirely lacking or much thicker and higher in 
the section, consisting of two phosphate beds separated by phosphatlc 
shales. The persistency of the shaly partings over large areas is 
considered doubtful, and development will undoubtedly show faces 
of phosphate beds which are as clean and as suitable for mining as 
those at Montpelier and Georgetown. 

About a mile west of Bloomington the following nearly complete 
section of the phosphate shales was measured. There is much local 
disturbance in the section, owing to the proximity of the margin 
of the thrust block, and it is highly probable that the section is some- 
what compressed and that the measurements may be less than would 
be found in an undisturbed section of the beds, such as might be 
encountered by drilling a mile or so to the east. 

Digitized by 



Section o/phosphatie skdUi erpoaatf in 8pmbwg'» timnd, in aec. $1, T. 14 S., R. 4S E. 

No. of 







M.185 n 

185 m 

186 1 
186 k 
186 1 
186 I 
186 h 
186 g 
186 1 

186 d 

LlmflBtoae, dark, with aaama or gypsura 

Shato, dark, cartxMiaoaous ? 

Clay, yellow to «i»y, aandy at wast 

PhoQMiate rook, gray and tnown, finely oaUtle . 

Phoq>hata rook, gray, ooazaaly oolitic 

FhoqAate rock, gray, xnedlmn ooUdo 

Phogphata rock, gray, fliMlyooUtlo 

Phosphate rock, gray, medium oolltto . 

Phoq>hate rook, grey and browiLflBfily oolitic 

Phosphate rock, grey, finely ooUtfto 

Fhoqkhatorook, grey, ooaraaly oolltJo^ weathered 

Phosphate rook, grey, finely ooUtte, much jointed, weathered . 



FL In. 


Shale, grey, finely ooUtto and sandy, muoh Johited and weath- 








101 21 

Fosaik occur at manj horizons in tiio phosphato-bearing member 
of the Park City formation and have been described by Girty ^ in a 
separate bulletin. 

The distinction between the phosphate-bearing strata and the 
underlying limestone is clear, but at its base the Paik City formation 
consists of calcareous sandstone and bands of quartzite alternating 
with limestone, so that it shows but slight difference from the calca- 
reous sandstones and sandy limestones which are belieyed to repre- 
sent the Weber quartzite. The under limestone in the northern part 
of the area possesses a fauna consisting, according to Girty/ mainly 
of Ohonetes ostiolatue, Proiudua aff. caneriniy P. aff. porreetus, P. aff. 
iveai, Rhynchopora taylori, CampoBUa mMMta, and Squanvularici sp. 
This member in the other districts has been found barren of fossils, 
and the presence here of a fauna so similar to that generally found 
in the overlying cherty limestone naturally led to the supposition 
that the section was overtumed, but the normal character of the 
sequence was soon clearly proved and the variation in abundance of 
fossils and difference in faunal character were determined. Owing 
to the local change in the character of the chert overlying the phos- 
phate shales, both lithologically and by the decrease in abundance 
of fossils, the lower limestone beconm an important marker in the 
prospecting of the phosphate beds. ¥^Mre favorably situated it 
weathers into conspicuous white cliffs, and as it practically forms the 
floor on which the lower high-grade bed was deposited, tihe location 
of that particular phosphate bed is very easily fotmd. 

1 Qirty, O. H., Fauna of the phosphate beds of the Park City formation tai Idaho, Wyoming, and Utah: 
Boll. U. 8. Qeol. Surrey No. 486, 1010. 
s Personal communication. 

Digitized by 





The Woodside limestone immediately overlies the Park City for- 
mation and is so called by coirelation with the section in the Park City 
mining district, Utah. It is composed mainly of thin-bedded, platy, 
somewhat shaly or sandy limestones. In the southern part of the 
area visited in 1910, including the Parid-Bloomington district, the 
upper portion of the Woodside formation includes "red beds" similar 
to those of the area farther south and east, examined in 1909. In the 
greater part of the region discussed in this report the ''red beds" axe 
absent, but some of the more massive beds in the upper part of the 
formation weather with a slightly reddish or purplish tint. The 
great mass of the formation consists of the thin beds above mentioned, 
which have a yellowish to olive-greenish tint and are firm textured 
and hard enough, when fresh, to ring under the hanmier. They 
weather to yellowish or brownish colors, usually retaining the slightly 
greenish tint. 

The base of the Woodside is quite distinct, for the upper cherty 
limestone of the Park City is usually well defined, in contrast with 
the overlying platy or muddy limestones. Even where the flinty- 
shale facies of the upper part of the Park City formation is present, 
the distinction between the float fragments of the two formations is 
usually so clear that the position of the stratigraphic boundary can 
be determined with Uttle difficiilty. 

The upper limit of the Woodside is not so clear. As this formation 
was originally defined in the Park City district it was intended to 
include the reddish shaly beds and to be limited by the more massive 
limestones of the overlying Thaynes. The distinction is perhaps not 
so clear in this field, but a more or less arbitrary limit may be <h*awn, 
which corresponds closely with the descriptions and thicknesses 
given for the typical sections. YiHtiere it has been recognized the 
Meekoceras zone has been adopted as a paleontologic definition of 
the base of the Thaynes. 

In the Paris-Bloomington district the upper Woodside consists of 
heavy limestones that weather reddish. Tlie actual transition into 
the beds that carry Meekoceras is not exposed, but the Meekoceras 
zone outcrops on the south side of the mouth of Paris Canyon in sec. 
10, T. 14 S., R. 43 E. This zone here consists of white, somewhat 
sandy limestones, weathering with a yellowish tinge. 

In sec. 5, T. 9 S., R. 43 E., and the adjoining township on the north 
a complete section of the Woodside is exposed. The lower and middle 
portions consist of thin-bedded platy and sandy limestone, of a yellow- 
ish to olive-green color, weathering brown. Alternating with this, 
especially in the middle portion, are somewhat thicker bedded 

Digitized by 



purplish-gray, yeUowish, or greeniah limestones. The upper portion 
of the formation consists of heavy-bedded, dense purplish-gray 
limestones that in some zones are crowded with fossils, principally 
species of MyaLma. The uppermost members of the heavy-bedded 
limestones pass into those containing Meekoceras with no perceptible 
lithologic or stratigraphic break. 


The "Thaynes limestone, overlying the Woocfcide shale in normal 
sequence, was named from its occurrence in Thajnes Canyon, near 
Park City, Utah. It contains marine fossil shells at many horizons, 
and from the occurrence of certain ammonoids (MeeJcoceras) at its 
b&se it has been assigned by Hyatt and Smith to the Lower Triassic.^ 
The Woodside shale, Thajnies limestone, and Ankareh shale were 
referred to the "Permo-Carboniferous'* by the Fortieth Parallel 
Survey. The '* Meekocerds beds,'' where recognized by the Hay den 
Survey, were referred to the Triassic. 

The Thaynes is distinguished chiefly by massive ledge-forming 
limestones which are in places abundantly fossiliferous. It also 
includes many shaly intervals and, to a minor extent, some brown- 
weathering calcareous sandstones that pass by gradations into the 
limestone. The limestone itself conmionly contains a considerable 
percentage of clay and sand, so that on weathering it assumes a 
sandy or muddy aspect, making much of it difficult to distinguish from 
sandstone except on fresh fractures. The thickness of the Thaynes 
limestone is somewhat lees than 2,000 feet as measured in Raymond 
Canyon, and the measurement obtained in MontpeUer Canyon shows 
at least that thickness, but it is doubtless several hundred feet thinner 
at other localities from which measurements have been recorded. 


The Ankareh shale of the Park City section was originally described 
from the exposures in Big Cottonwood Canyon, near Salt Lake City. 
It consists chiefly of clay shale of deep maroon and chocolate colors ^ 
massive where fresh, though commonly breaking down with exposure 
into thinner-bedded shaly material. It includes also some pale-green- 
ish clayey and sandy strata, beds of mottled green and maroon shale, 
and harder layers of red or greenish sandstone and limy strata, and 
in the MontpeUer district is defined at the top and bottom by massive 
limestones. The limestone or calcareous shale at the top distinguishes 
the Ankareh to the south from the massive sandstones and red sandy 
shales of the Nugget sandstone. The limestone at the base of this 
"red bed" formation is the uppermost of the massive beds that con- 

1 Hyatt, Alpbeas, and Smith, J. P., Tlia Ttlassio oephalopod genera of America: Prof. Paper U. S. Oeol. 
Survey No. 40, 1906, pp. 17 et seq. 

Digitized by 



stitute the more promment part of the Thaynes limestone. The total 
thicknees of the Ankareh m meosured in its Montpcdier district is 
about 670 feet, including tbe limesteniD at the top, but excluding the 
massive underlying sandstone strata more properly classed with the 
main body of the Thaynes. The thidmess in this area is about the 
same as in the Montpeher district. 

CRBTAOBOirS (P) &00X8. 

Associated with the sulphur deposits in T. 9 S., B. 42 E., there is a 
white rock which resembles a fine-grained sandstone but under the 
microscope is found to consist of angular particles of glass. This 
rock is apparently sedimentary. The fault agglomerate in which the 
sulphur is deposited includes fragments of this tuff associated with 
fragments of Carboniferous quartzite and limestone and Triassic ( ?) 
limestone. It is older than Cretaceous, the supposed age of the fault- 
ing. W. R. Calvert,* of the United States Geological Survey, sug- 
gests that this tuff may have been deposited during the same period 
of volcanic activity as the Livingston formation of Montana, which 
Stone and Calvert ' have shown to range in age from lower Montana 
to Fort Union, inclusive. 



The beds of the r^on which are younger than those of Triassic ( !) 
age lie unconfoimably upon the older strata. The unconformity is 
great, for the oldest rocks above the Triassic (f), with the exception 
of the volcanic tuff, which because of its relations to the faults of the 
area is regarded as possibly of Cretaceous age, are lake beds not older 
than Eocene. These lake beds are conglomeratic and are best exposed 
on the hills forming the east flank of the Bear River Range in the 
vicinity of Bloomington and to the south. In places they are dark 
red, unevenly bedded, and made up mainly of bowlders derived from 
the Paleozoic quartzites. They are lithologically and stratigraph- 
ically equivalent to the lower portion of the Eocene beds south and 
east of Bear Lake and undoubtedly correspond to the Almy con- 
glomerate of Veatch.* In the north^n part of the area they are not 
present in sufficient amount to warrant mapping. SmaU patches of 
conglomerates which may represent them were seen about 2 miles 
north of Liberty, in T. 12 S., R. 43 E. 

1 Fenonal oommnnlcatioo. 

* Stone, R. W., and CalTert, W. R., Stntlgmphic relations of the LirlngBton formation of Montuia: 
Boon. Geology, vol. 6, No. 6, pp. 161; Ko. 7, pp. M2-669; No. 8, pp. 741>704. 

s Veatdi, A. C, Geography and geology of a portion of sontheastam Wyoming, with special reference to 
ooal and oil: Prof. Paper U. 8. Ged. Sarvey No. 56, 1907, p. 80. 

Digitized by 




Maris, marly limestones, calcareous grits, and calcareous conglom- 
erates, of probable Plioceuie age, which were included in the Salt 
Lake group of H^tyden ^ and Peale,^ fringe Bear Lake Valley on its 
'west side, fonning a t^race-like border about the Paleozoic and Meso- 
zoic sediments. Farther north, in the region between Bern and 
I^ounan, the deposits run up to the tops of the high hills, and the de- 
formation of the beds is made very apparent by the presence of dips 
as high as 50^. In the middle of the area in the vicinity of George- 
town similar deposits lie near the present valley level in nearly hori- 
zontal position. But on the hill imnctediately east of Novene station 
the same beds have been so folded that they rise with the eastern 
slope and cap the hilltop. The extensive travertine deposits which 
extend from this vicinity northward to Sulphur Canyon appear to 
dovetail with the lake deposits, and their close litholqgic resemblances 
render the areal distinctions difficult. These supposed PUocene de- 
posits may be in part fluviatile, and the apparent deformation may 
be due in part to inclined deposition. 

OnrAVBBirABT dbfosits. 


The four townships in the northwestern portion of the area are 
covered in part by flows of dark-colored igneous rocks, which repre- 
sent the southern lobes of the outpourings of the craters situated 
between Soda Springs Hills and Blackfoot Marsh, 3 to 6 miles north 
of the area shown on Plate IX. The rocks of these flows are called 
basalts throughout this report. They have been so described in the 
earlier papers on this region,* and their mineralogical constitution and 
dark color warrant the determination. Examination with the naked 
eye shows the presence of phenocrysts of yellowish-brown glassy oli- 
vine and areas of transparent cleavable calcite, which is undoubtedly 
secondary, inclosed in a dark aphanitic groundmass. 

The greater part of the basalt is dense, and in cliffs shows the devel- 
opment of irregular coliminar jointing, but minor scoriaceous and 
cellular facies are found, especially near the margins of the flows. 
The surface of the basalt has a comparatively fresh and recent ap- 
pearance, and the soil cover is thin except where it has been aug- 
mented by alluvial agencies. The number of flows has not yet been 
worked out in detail. It is evident that there are several, because of 
the intercalation of scoriaceous and tuffaceous lentils. The exact 
geologic range of the flows has not been determined, but it appears 
that some at least, from their relation to the deformed limestones of 
probable Pliocene age, toe as late as early Quaternary. 

> Haydn, F. V., Fifth Am. Bspt U. 8. 0«al. and Qeog. Borray Terr., for 1871, 1872, pp. 1£4, 165. 

< Baato, A. C, Steventti Aon. Bapt U. S. Gaol, and Gaog. Survay Terr., for 1877, 1879, pp. M8 640. 

< Fifth Ann. Rapt. U. S. Gaol, and Gaog. Sarvey Terr., 1872. 


zed by Google 


■psnro BXMsrri. 

The portion of the area described in this report from the vicinity of 
the south boundary of T. 10 S., R. 43 E., to the northern margin is 
characterized by the presence of extensive deposits of travertine and 
numerous springs, many of which are depositmg tufa at the present 
time. The largest group of springs, in the neighborhood of Soda 
Springs, afforded a rendezvous for the Indians and the early voy- 
agers and trappers. Washington Irving's accounts of the gatherings 
at the ^'Beer Springs'' ^ are vivid and clearly present the fascination 
which the natural effervescing waters possess. Frftnont * described 
the springs in considerable detail and prepared the first map of the 
locality. Hayden* visited the springs in 1871 and Peaie * in 1877. 
Peale gave an excellent accoimt containing a laige amount of new 
data which he compared with the earlier records. The prophecy that 
the springs would become one of the great pleasure resorts and water- 
ing places of the country has not yet been fulfilled, probably because 
of their proximity to the Yellowstone National Park with its greater 
variety of natural wonders, and because of the fact that a commu- 
nity in which sheep grazing is the principal industry is not particu- 
larly agreeable to the seeker of pleasure or health. 

The natural carbonated water is exploited conunercially xmder the 
trade name Idanha and the water is sold extensively through the 
Northwest, occasional shipments being made as far east as Chicago 
and Milwaukee. The water has an agreeable taste and pungency, 
and the content of mineral matter averages 152 grains to the United 
States wine gallon (2,599 parts per million). 

The other springs of the vicinity are said to vary in character and 
amount of salts from the spring which yields the Idanha water. The 
water from certain of the springs is higher in magnesium salts ; in others 
the iron salts are especially abundant. Mammoth Spring, in T. 8 S., 
R. 41 E., is one of the springs discharging a large amount of carbon 
dioxide. Its daily discharge is reported to average 2,000,000 cubic feet. 

The extensive travertine deposits in the vicinity of Formation 
Spring and Swan Lake Gulch are especially remarkable and repre- 
sent remnants of spring basins which during the period of maximum 
spring activity exceeded in size the present basins of the Yellow- 
stone National Park. The deposition of the calcium carbonate is 
clearly due to the loss of carbon dioxide, for as a general rule the 
waters do not deposit at the point of emergence, but after running a 
distance, which appears to vary with the declivity. The faster flow- 
ing waters lose their gas more rapidly and deposit nearer the springs. 

1 AdTontoras of Capt BonnsyUle, or Scenes beyond tbe Rooky Hountaiiui of tbe Far West, Phlladelphit, 
1887; London, 1850. 

* Fffoiont, J. C, Report of tbe exploring expedition to tbe Rocky Moonteins In tbe year 1842, and to 
Ongon and CaUtomla in tbe years 1848^44: Senftte Doc. 170, House Doo. 166, 28tb Cong., 2d sess., 1846. 

• Hayden, F. V., FIftb Ann. Rept. U. 8. Qeol. and Oeog. Sorvey Ten., 1872. p. 164. 
« Peale, A. C, Eleventb Ann. Rept U. 8. Qeol. and Oeog. Survey Terr., 1879, pp. 500-606. 

Digitized by 




The major structural features of the region are the broad synclinal 
troughs and broken intervening anticlinal ridges of the Aspen Range 
and the great folded and overthrust mass of the Bear River Range. 

In Bear Lake Valley the structure is problematical, being con- 
cealed by alluvium. 

The details of the structure of the Aspen Range are included in the 
portions of the report dealing with Tps. 8 and 9 S., Rs. 42 and 43 E. 

The great overthrust from the west, the trace of which nms through 
the area from north to south, is a striking example of the overriding 
of younger sediments by older and harder formations which takes 
place when the shortening of the strata accomplished by folding is 
not sufficient to relieve the compressive strain. The force appar- 
ently originated to the west of this area and acted toward the east. 
The overthrust is similar to and probably a direct continuation of 
the thrust fault observed in the Woodruflf Creek area, Utah,* in 1909. 
If the structures in the two areas are really continuous, the fault has 
a known length of about 100 miles and an apparent horizontal dis- 
placement of about 10 miles. 

The origin of Bear Lake Valley is a problem both structurally and 
physiographically. The length of the valley from Bennington, Idaho, 
to Laketown, Utah, is about 36 miles, and the width at the Idaho- 
Utah line is a little over 7} miles. The valley includes an area of 
about 180 square miles, two-thirds of which is in Idaho. It is shut 
in on both sides by mountains. The direction of outflow in earlier 
times is unknown, but was presumably northward, as at present. 

The valley wall, especially along the east side of Bear Lake, is 
strikingly scarplike when viewed from the opposite side of the lake. 
This, together with the occurrence of several thermal springs on the 
margin of the alluvial plain near the base of the mountains at Hot 
Springs, Idaho, suggest that this side of the valley is determined by 
the presence of a fault extending to considerable depth. The west 
side of the valley has also, to a lesser extent, a scarplike appearance, 
although the structure of the exposed rocks permits also the postu- 
lation of a down folding of the beds below the present valley level. 

A brief summary of the geologic conditions existing in the areas 
adjoining the valley may be given as an introduction to a discussion 
of the inferences concerning the conditions existing under the alluvial 
valley cover. 

The area directly west of the valley is occupied by a rock series 
ranging from Madison limestone to Thaynes limestone, Mississippian, 
and Triassic (?), respectively, emerging from under an overthrust 
block of sediments that are mainly of Cambrian age but include in the 
vicinity of St. Charles rocks of a somewhat more recent aspect. The 

> Oale, H. 8., and BidiMda, B. W., BnU. U. 8. GeoL Bmyej No. «Q, 1910^ p. fi27. 

Digitized by VjOOQIC 


east edge of the overthrust block lies at a maximum 4 miles back 
from the valley margin toward the north end of the valley, but so 
far as is known practically coincides with it in the vicinity of St. 
Charles and to the south of that point. 

The geologic structure on the east side of Bear Lake Valley ^ is 
that of a series of large easterly overturned anticlines and synclines. 
The valley margin cuts somewhat obliquely across the axis of an 
overturned anticlinal fold from the vicinity of Dingle to the Utah 

The geologic structure in the northern part of the valley is best 
exposed east of Novene station, where a portion of the Thaynes 
limestone lies close by an area of Madison limestone. The exact 
nature of the relation between the two is obscured by a cover of 
Tertiary lake beds, but it is supposed to be a fault contact along the 
line of disturbance of a fault zone which may form the eastern bound- 
ary of the valley. It is probable that this same line of dislocation 
extends to the north along the line of extensive spring deposits near 
Swan Lakes, Sulphur Springs, and Formation Spring. 

A geologic section across the south end of Bear Lake Valley, in 
Utah,^ involves a folded series of Cambrian to Mississippian sediments 
on the west overthrust on a block of Mississippian to Jurassic folded 
rocks on the east. 

The above review of the geologic conditions existing in the areas 
surrounding Bear Lake Valley suggests the following conclusions: 

1. A fault or a series of nearly parallel faults, probably normal 
because of the presence of hot and depositing springs and possibly 
of considerable length, extends along the west front of the Aspen 
range and southward into and along the east side of Bear Lake Val- 
ley, possibly passing out of this valley to the south along the same 
line as the thrust found between the Cambrian and Mississippian 
and the block including the later sediments. The downthrow is 
everywhere on the west side of the fault, and the amount of displace- 
ment is greater toward the north than in the southern part of the 

2. A displacement has occurred along the west side of Bear Lake 
Valley, either by downfolding or by faidting, the effect being in both 
cases practically the same — ^viz, to place postphosphate rocks in 
unknown distribution and at unknown depths below the valley floor. 

3. A fault of less throw than that of the one supposed to bound 
the valley on the east may be regarded as branching from the major 
fault in the vicinity of Wooleys and extending along the wegtem 
margin of the valley, as indicated on Plate DL This may, perhaps, 

1 Gala, H. S., amd Btobwdt, B. W., BolL U. a O0OIL Survey No. 4», Mti^ p. 4B8. 
> Idam, p. 522. 

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be considered ae offerii^ the simpleet «3q)lanat]an oi the observed 
conditions. Whether or not such a fault passes through the rock 
series in the southwest comer of the valley is unknown. 

Bear Lake Valley, therefore, probably constitutes a true graben, 
or downthrown fault block. The north end of the graben tapers; the 
nature of the south end is obscure, and no attempt is made to explain 
it at this time. 

Pecde * suggested that Bear Lake Valley is probably tmderlain by 
at least one anticlinal fold. The recent work in the region between 
Bloomington and Liberty has disclosed evidence of an anticlinal axis 
east of the syncKne involving Triassic ( ?) rocks which comes out from 
under the overthrust Uock of Cambrian quartzites and limestones. 
This fold lies a little to the east of the present west border of the val- 
ley. The existence of another anticlinal axis along the eastern 
margin of the valley has already been mentioned. A parallel inter- 
vening syncline probably intervenes between these anticlines. It 
appears rather unhkely that this syncline is of a sufficiently greater 
order than the exposed folds to occupy the entire valley. More 
probably the valley area was originally spanned by a series of anti- 
clines and synelines, in part at least overturned toward the east in 
a mannw similar to that of the exposed lower anticHnal limb of the 
east side of the valley in the vicinity of Hot Springs. 

A diagrammatic cross section across the valley is shown on Plate IX. 
The portion of the section based on information derived from the 
outcrop is shown in solid line; the inferred portions are indicated by 
broken lines. In the construction of this section the intervening 
unknown folds were assumed to be approximately of the same order 
as the known folds, and it was assumed that the eastern part of the 
intervening folded series is overturned like the folds observed farther 
east. One of the folds of this valley area was probably of sufficient 
magnitude to afford an origin for the overthrust of Madison lime- 
stone in the vicinity of Montpelier. 

The period of overturning and ov^rthrusting was succeeded by a 
period of relaxation and settling in which adjustment took place 
mainly by normal faulting. The evidence of such faulting in the 
immediate vicinity of Bear Lake Valley has been presetted in the 
foregoing discussion. The fault of tHe greatest moment extends 
along a line connecting Formation Spring and Hot Springs, forming 
the eastern margin of the valley. The downthrow in all places is on 
the west and the fault plane dips in that direction. The Aspen Range 
contains abundant normal faults which presumably came into exist- 
ence dxuring the same period of structural readjustment that to a large 
extent determined the shape and size of Bear Lake Valley. 

1 Peate» A. C, Elevwth Aan. RepU U. 8. €M. and Geog. Bwmj T«rr. for 1877, 1879, p. 588. 

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The area examined in 1910 comprised 15 townships in Rs. 41, 42^ 
and 43 E. of the Boise meridian. These townships were included 
either in whole or in part in the phosphate reserves as originally con- 
stituted by the withdrawals of December, 1908, and December, 1909. 

Reconnaissance examinations were found sufficient for nine of 
these townships, in which laige areas of prephosphate rocks existed 
and the phosphate deposits were indicated mainly by the normally 
overlying formations. The remaining six townships contained the 
phosphate deposits and the rocks immediately associated with them, 
both normally above and below. The areas of these rocks were 
complicated by both folding and faulting, so that detailed geologic 
mapping was essential in the study of the deposits. 

T. 8 S., B. 41 E. 

A reconnaissance of T. 8 S., R. 41 E., demonstrated the absence of 
the phosphate-bearing strata, at least in outcrop, and accordingly the 
geology was not mapped in detail. The location of the places at which 
information was coUect'Cd was determined by means of the map 
made by the Hayden Survey in 1877, and the geologic mappiog of 
the township on Plate IX is a compilation of the new data and those 
of the earlier survey. 

The sedimentary rocks range in age from Cambrian to upper 
Mississippian and outcrop only in the southwestern half of the town- 
ship, and the series is in ascending order from southwest to northeast. 
Basaltic flows cover the northern and eastern portions of the township 
and entirely conceal the underlying sediments. 

The strike and dip of the rocks, so far as observed, together with the 
distribution of the several formatiens and the supposed Cambrian 
outlier on Threemile Hill in T. 8 S., R. 42 E., suggest that the main 
structural feature is a rather open syncline with a northwest-southeast 
axis. The great easterly overthrust of the Bear River Range is pro- 
jected west of the exposure on Threemile Hill across the northeast 
comer of the township under the basaltic cover along the general line 
of strike of its trace. More detailed work will doubtless show many 
minor faults within the area. 

The limestones in the southwest comer of the township are dark 
gray or bluish gray in color, are dense, and contain fragments of 
trilobites. These, together with the associated sandy limestones, are 
considered of Cambrian age. The overlying beds, comprising a series 
of gray limestones, contain fossils which are pronounced by E. 0. 
Uhich to be of Beekmantown (Lower Ordovician) age and the fauna 
is similar to that collected by the geologists of the Hayden Survey at 

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M alade, Idaho, about 33 miles southwest of this locality. Near the 
top the limestone includes a small amount of yellow-banded chert, 
and it is overlain by a glassy white quartzite which should probably 
also be included in the Ordovician. Fossils collected from a series 
of darker and more or less brecciated limestones which may lie 
conformably above the quartzite have been identified by Ulrich 
as representing the basal portion of the Silurian system. About 600 
feet higher corals were found which are regarded by E. M. Kindle as 
probably representing the fauna of the Jefferson limestone (Devonian). 

The Carboniferous system is represented by limestones outcropping 
in the higher of the Soda Springs Hills, which lie in a northwest- 
southeast diagonal across the township. These rocks are referred by 
G. H. Oirty to the Madison limestone Gower Mississippian) and the 
upper Misdssippian. 

It is doubtful if sediments later than these are exposed with the 
exception of Tertiary lake beds. The basaltic flows are at least in 
part Pleistocene^ but possibly in part older. 

The portion of the township in which the sediments outcrop does 
not contain rocks as young as the phosphate-bearing Park City for- 
mation; and if this formation is present it is concealed by the basaltic 
cover. The general character of the syncline suggests that phosphate 
deposits are not included in the central portion of the township. It 
is possible, however, that such deposits exist in the northeast comer 
to the east of the great thrust fault. 

T. S., B. 41 E. 

T. 9 S., R. 41 E., was not mapped in detail in the present work, 
but a reconnaissance examination was made along the southern and 
northern boundaries and neither the Park City formation nor the 
normally overlying formations outcrop. The general geology of the 
township as shown on Plate IX is compiled from the data recently 
collected and from the work of the Hayden Survey. 

The geologic structure has not been worked out in detail, but it 
may be stated broadly that the strata are deformed in large folds 
and that the structure is further complicated by faults. 

The geologic sequence so far as studied includes formations of 
Cambrian to Mississippian age overlapped by much later rocks — 
Tertiary lake beds, basalt flows, travertine, and alluvium. 

The details of the Paleozoic section, as exposed in the northern 
part of the township, are as follows: light yellowish-gray sandy 
limestone outcropping in the sides of an irrigation ditch on the point 
directly west of Alexander apparently represents the oldest sediment. 
Above it is an iron-stained limestone with a few beds of soft hematitic 
shale, succeeded by clear bluish-gray limestones whose Cambrian 
age is indicated by abundant fragments of trilobites. These in 

94174 *•— Bull. 470—11 2d 

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turn give way to sandy limestones and breccias of similar lithologic 
character^ which in places show clear evidence of a later period of 
movement, probably normal faulting. One especially interesting 
fissure tapered upward and held a calcareous filling. The amount 
of displacement could not be ascertained and no metalliferous values 
were apparent. Still higher in the section, provided that the dis- 
placements have not been great in amount; clearer limestones again 
predominate and in this part of the section they carry a fairly abund- 
ant Ordovician fauna. They are succeeded by a dense white quarts- 
ite, to the east of which is found a series of limestones apparently 
ranging from Silurian to Mississippian in age. 

The eastern and western portions of the township are covered by 
basalt flows which apparently cross the township along the valley 
of Bear River. The lava was supplied from two sources — the group 
of craters in T. 7 N., R. 41 E., and the craters in Basalt Valley imme- 
diately west of the township. 

In the vicinity of Soda Springs and to the west, in Spring Basin, 
varicolored travertine is the most conspicuous surficial deposit. This 
is the product of the many springs which yield carbonated waters. 
In those places where the travertine is white it somewhat resembles 
an alkali flat in appearance, but it supports a heavy growth of cedar 
or, where cultivated, fair crop>s. Near the place where Soda Springs 
Creek enters Bear River, Steamboat Spring, a thermal spring, still 
appears as active as when described by Bonneville, Fr&nont, and 

The Park City formation is not foimd in the township, and as com- 
mercially available phosphates are not known in any other formation 
of the region, such deposits are inferred to be absent. 

T. 8 S., B. 42 E. 


A detailed geologic survey of the eastern half of T. 8 S., R. 42 E., 
was made with a Johnson plane table and Oale telescopic alidade, 
the locations being found on the base map, which had been prepared 
in advance by Albert Pike, by either the station method or stadia 
traverse. The location of the outcrops of the base of the phosphate 
series was determined with as high a degree of accuracy as the con- 
ditions of exposure and the field mapping scale of 1:31,680 would 
permit. The map of the township (PI. X) accompanying this report 
is a reduction from the field map. 


The entire western half of the township with the exception of 
Threemile Hill ip covered by basaltic flows which were poured out 
by the group of craters 3 to 6 mile^ north of the township. Evidence 

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- + 


■IV^ + 

t + A-S + + 

+ x^ ■ 
+ \ + 

+\ + 




+ + 


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of the existence of several flows was noted, but sufficient data have 
not been collected for a statement of the number or of the variation 
in lithologic character of the different sheets. Scoriaceous agglom- 
erates and beds of tuff are included in the volcanic series. The age 
of the flows was not definitely ascertained, but limestones in sec. 33 
which are regarded as Pliocene were clearly deformed prior to the 
eiztrasion of the lava, which embayed their outcrops, establishing 
the probability that at least this particular flow is Pleistocene. 

The spring deposits are calcareous travertines and are mainly later 
in age than the basaltic flows, although minor exceptions were noted. 
Formation Spring is the lai^est of the springs in this portion of the 
area and is named from its extensive travertine deposits, which form 
an elaborate set of basins. 

The Tertiary sediments are composed of drab to white limestones, 
which vary in grain and degree of compactness from loosely con- 
solidated marly varieties to a dense, nearly lithographic f acies which 
looks older than Tertiary. The fossils found are few in number of 
species and imfortunately have a wide geologic range, and for the 
present the Pliocene classification of these beds by the Hayden Survey 
is accepted. 

The Woodside as exposed in this township consists of rusty brown 
shales, shaly limestones, and a minor amoimt of clear bluish lime* 
stone which is with difficulty distinguished on purely lithologic evi- 
dence from the older limestones of the early Pennsylvanian or the 
late Mississippian. Fossils are so abimdant, however, that doubt 
as to the identification of a particular outcrop can usually be cleared. 

The presence of a heavy tahis effectuaUy conceals the upper part 
of the phosphate shales in this township and no prospecting has yet 
been done upon that portion of the beds, so that it is impossible to 
compare the entire section with the complete section measured in 
Georgetown Canyon. All that may be said in this respect is that 
the partial section measured in Trail Canyon (p. 390), though not 
showing so high grade a bed at its base, yet contains for the propor- 
tion of the series exposed a relatively greater amount of commercially 
available phosphate. 

The sediments imderlying the Park City formation consist of a 
series of gray limestones much seamed with calcite, sandy limestones, 
and calcareous quartzites, with locally brecciated zones containing 
angular ashy-gray chert fragments, which when weathered out into 
brownish nubs are conspicuous, and in most places still higher in the 
series a geodal limestone spotted with small quartz-lined cavities. 
Heavy massive beds of quartzite such as characterize the Weber 
quartzite in the areas examined by Gale and Richards in 1909 are 
absent, and approximately the 1,000 feet of beds occupying the same 
position in the section consist of poorly exposed soft sandstones and 
earthy limestones, which locally have reddish tints. The limestonesi 


zed by Google 


ixnmediatelj underlying these beds for a stratigraphic interval of 
about 500 feet are considered of Pennsylvanian age by Girty,^ on 
faunal evidence, and are provisionally correlated with the Morgan 
formation of Utah. The remaining series to the exposed base 
includes both upper Mississippian and a portion of the true Madison 
limestone Gower Mississippian). 

The township includes along its eastern border a portion of the 
west flank of the Trail Creek syncline and to the west at least 
two other synclinal folds with the broken renmants of intervening 
anticlines. The fracturing of the anticlinal structures has given rise 
to a complicated set of faults, both thrust and normal. Evidence of 
a major thrust fault bringing supposed Cambrian rocks over Triassic 
rocks is found on Threemile Hill, in sec. 29, and this identical re- 
lation is produced by the thrust that is found to the south. A line 
dravni a short distance west of this outlier to the last exposure of the 
fault in T. 10 S., R. 43 E., is the only suggestion that can be given of 
the position of the trace of the fault under the cover of basalt and lake 
beds. The extension of the same line to the northwest indicates a 
theoretical position for the fault under the basaltic cover in that di- 
rection. The known stratigraphic magnitude and linear extent of 
this fault to the south warrants such a northwestward extension. 
The uneroded phosphate deposits occur in synclines, with the excep- 
tion of the deposit in sec. 2, where the highest mountain in the 
township is capped by an anticlinal arch of the chert which imme- 
diately overlies the phosphate-bearing portion of the Park (Aty for- 


The prospecting m this township has been carried on mainly by 
open cuts, and most of these are in the basal portion of the phos- 
phatic shales. The beds in many places are nearly horizontal and the 
rock is very much broken and jointed, so that the information gath- 
ered is for the most part limited to the basal bed. The most com- 
plete section obtained was measured in sec. 25 on the north side of 
Trail Canyon and is given on page 390 of this report. It shows that 
7 to 10 feet of high-grade phosphate rock is included in the lower por- 
tion of the phosphatic shales. A comparison of this section with 
some which have been made by L. P. Brown in other parts of the 
township shows that it can be regarded as typical. 

Many of the sections measured by the survey were partial owing to 
the caved condition of the prospects, and the samples obtained are 
unsatisfactory because of the inclusion of soil in the joints of the 
broken phosphate, a condition which would undoubtedly not exist 
where mining had been done more recently. The details of these 

^Otrty, G. H.» Fauna of the phosphate beds of the Park City fonnatioa in Idaho, Wjoimtag, and 
Utah: Bull. U. 8. Geol. Survey No. 436, 1910, p. 7. 

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sections and the analjBes are therefore omitted from the present 

The only shipment of phosphate rock which has been reported 
from this township was made early in the simmier of 1910, from a 
prospect in the SE. J SW. J sec. 23, by Brown, Perlrins & Co. The 
shipment, which is said to have consisted of 40 tons, is reported to 
have contained 34.14 per cent of phosphoric acid, equivalent to 74.6 
per cent of tricaldum phosphate. A check analysis of the buyer's 
sample by J. G.Fairchild in the laboratory of the United States Geo- 
logical Survey showed 34.23 per cent of phosphoric acid. The pros- 
pect from which the shipment was made was examined and the fol- 
lowing section measured: 

Section o/phaaphate bed in Agnes daim, in sec. tS, T.8S.yR.4X E, 

No. of 




lent to 



H 636-4 

Phosphfttlc rock, brownish gny, TnnHhitn oolitic. . 



Ft. in. 
2 1 


^hcephatio rocV,' brown to gjt^y', iSno to mwlluxn oolitic 

2 1 


Phosphatio rock', brown, finely oolitic, slightly sandy 

2 1 


Phoq>hatlc lockj farownj fins to medium ooll^. ... I 

2 1 

8 4 

' The prospect is located on the axis of a small westerly overturned 
syncline, and the apparent thickness of phosphate rock exposed in the 
prospect is nearly twice that of the above section. 

The portion of the township covered with basalt may contain ex- 
tensive areas of phosphates and postphosphate rocks, but it is ex- 
cluded from consideration in the following estimate of acreage. Ap- 
proximately 5,000 acres of land is clearly underlain by the phosphatio 
shales of the Park City formation and for purposes of estimate the 
thickness of the minable 70 per cent rock is taken as 7 feet. The 
computation is most readily made by regarding the deposits as lying 
horizontally throughout the area. Such an assumption takes into ' 
account less than the actual content of the deformed beds and may 
be accepted us conservative. On the assumption stated the phos- 
phate lands contain in round numbers 122,500,000 long tons of rock 
phosphate. The thickness of the cover over these deposits does not 
exceed a maximum of 1,000 feet, and a large portion of the phosphate 
is probably above the ground-water level, as indicated by the eleva- 
tion of the springs. 

T. S., B. 42 E. 


The partial topographic and geologic survey of T. 9 S., R. 42 E., 
necessary for the investigation of the phosphate deposits was made 
by J. H. Bridges. The work was done with a plane table and mainly 
by the station or triangulation method of location. 

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A more complete discussion of the several formations present in 
this township will be found on pages 380-396, but a brief statement 
concerning each of the formations is included here. (See PL XI.) 

The obviously alluvial deposits are limited to the muds, sands, and 
gravels of the Bear River valley and the similar deposits in and 
about the openings of the several canyons upon the plain whidi 
makes up the northwestern and central parts of the township. 

Calcareous spring deposits occupy extensive areas within this 
township and locally are distinguished with difficulty from the softer 
limestones of the Pliocene (t) beds. They are also associated with the 
finely comminuted deposit of white volcanic glass in the fault agglom- 
erate or breccia near the sulphur deposits. A series of basaltic 
flows entered the township from the craters to the northwest and 
extended as far south as the river. The surface of the basalt is still 
unweathered, in places, and several cliffs along the maigin afford 
examples of colimmar jointing. The thickness of the several flows 
as reported in wells drilled by A. O. Kugler is as follows: 

Section of well in ike NE, J NW. i sec. £t, T. 9 S., R. 4t E, 


Alluvium, light-colored soil) sand and gravel 45 

Basalt 17 

Alluvium, light colored 48 

Baaalt 65 

SecHon of well in see, tO, T. 9 8., R, 4t E. 

Baj9alt 110 

Shale, carbonaceous 4 

Clay, white (travertine ?) 10 

Basalt 4 

Sand, yellow 16 


No attempt is made to correlate the several flows or to estimate 
their number, but their age, if the interpretation assigned by Peale * 
to the fossils collected by Hayden^ is correct, is later than early 

The area intervening between the faults in sees. 2, 11, 13, and 
15 is occupied by an agglomerate composed of angular fragments 
of Triassic (?) limestones, Carboniferous limestones and quartzites, 
and a volcanic tuff or ash. The tuff is snow white, fine grained, 
and composed of minute angular glass fragments. In sec. 11, 

1 Eleventh Ann. Kept. U. S. Qeol. and Geog. Surrey Terr., for 1877, 1879, p. 689. 
* Fifth Ann. Kept. U. S. Qeol. and Oeog. Survey Terr., for 1871, 1872, p. 154. 

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U. 8. i 



















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near the northenunost of the sulphur prospects, the tuff is the 
country rock for an area of approximately half an acre. It ia, 
however; much broken, and is regarded as lying within the fault 
zone. The relation of the ash to the other rocks is not clear, but 
the presence of angular masses of it within the agglomerate indicates 
that it was deposited prior to the faulting. The age of the faulting 
is not locally determinable more closely than that it is post-Triassic, 
but comparison with other parallel faults, of which the CokeyiUe 
(Wyo.) fault described in the 1909 report * may be taken as a type, 
it is probably late Cretaceous. The age of the tuff, then, is Creta- 
ceous or earlier. The sulphur deposits are described in a separate 
chapter of this bulletin. 

The deposits which were considered of Pliocene age by Peale 
consist of close-grained, nearly lithographic limestones, which are best 
seen in sees. 3 and 4, and soft marly limestones and calcareous 
conglomerates, which are best exposed on the south side of Bear 
RiTcr. No additional data relative to the age of these rocks have 
been collected. The only fossils found have a wide stratigraphic 

The portions of the township mapped as Triassic (?) were so 
determined by the presence in tiie float of predominating amounts 
of fragments of the rusty bronze-brown shales and shaly limestone 
carrying fossils characteristic of the Woodside limestone. So far as 
is known the only outcrops of the formation clearly in place protrude 
through the loose weathered material which covers the surface in 
sees. 24 and 25, and most of the area shown as Triassic ( t) might 
equally weU be designated Quaternary hill wash. 

The Park City formation outcrops over only a small area in sees. 
1 and 12 and is represented mainly by the black chert which overlies 
the phosphatic shales and phosphate beds of the section. 

The formation is bent up in a sharp syncline with minor folds on 
its western limb. The phosphatic shales are exposed and an abund- 
ance of high-grade float was found along the west side of the fold, 
except where the beds are cut out by the thrust fault. This fault 
appears to pass under the syncline and into the normal fault to the 

The portion of the western front of the Aspen Range which occu- 
pies the northeast comer of this township is composed mainly of 
massive gray limestones, yellowish and reddish sandy limestones, 
and calcareous quartzites. These beds are deformed in large folds 
which are apparently overturned toward the east. The rocks range 
in age from early Pennsylvanian to late Mississippian, and comprise 
the Weber (?) formation, the Moi^an (?) formation, an unnamed 

1 BuIL U. S. OeoL Survey No. 430, 1910, p. 606. 

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intenral of upper Mississippian strata, and the Madison lime- 

The areift west of the concealed fault which crosses the township 
in a northwest-southeast direction is underlain by early Paleozoic 
sediments, probably Cambrian. A small outcrop of rocks, presum- 
ably of Cambrian age, was noted by Mr. Bridges as protruding throu^ 
the alluyium in sec. 32- about 400 feet northwest of T. J. Hopkins's 

The major fault of the area is the overthrust concealed by the 
cover of basalt and lake beds which to the north and south is known 
to cause sediments of Cambrian age to override rocks as late as 
Triassic (?). The position of the fault as indicated is, of course, 
approximate and its presence is hypothetical. 

This thrust is roughly paralleled by a series of branching normal 
faults which intersect in the vicinity of the sulphur springs and the 
sulphur deposits in the eastern part of the township. A minor 
thrust underlies the area of Park City chert in the northeast comer 
of the township. 


No prospects were found in the township showing oolitic phos- 
phatic rock, but one or two shallow openings have been made in the 
phosphatic shales. Abundant float of the high-grade rock phos- 
phate afforded evidence of the presence of the richer beds. The 
area west of the normal fault series and east of the great thrust pre- 
sumably contains the phosphate deposits at depth. 

The quality of the rock phosphate as inferred from the adjoining 
townships is on the average equivalent to 70 per cent tricalcium 
phosphate, although the float rock would probably run above that 
figure. An average of 70 per cent would doubtless be fair for these 
deposits, and it is reasonable to assume the presence of 6 feet of such 
rock in the section. The area in which the portion of the Park City 
formation overlying the phosphate beds actually outcrops comprises 
about 200 acres, and about 3,200 acres may conservatively be regarded 
as representing the outcrop area of the Woodside limestone, the 
formation next overlying tiie Park Qty formation. 

The assumption that 3,200 acres of land in the township is under-